If you’re an Amazon devotee you have to hope this honor isn’t the equivalent of the Sports Illustrated cover jinx because as successful as Amazon is — in online retail, in publishing, and in cloud infrastructure services — it faces very big challenges.

For one thing, the sales tax advantage Amazon’s retail business has enjoyed for 16 years is evaporating as more states are forcing it to charge sales taxes on in-state purchases. That could erase some of its traditional advantages over brick-and-mortar stores.

And, Amazon Web Services, the company’s giant IT infrastructure business, faces growing competition as well from players like Rackspace, IBM, VMware, Joyent, SoftLayer and others. In addition, at a time when AWS is trying to lure more enterprise workloads, it’s seen its share of embarrassing snafus including an issue at its US-East data center on Christmas Eve which brought down Netflix streaming video. Netflix is both a big Amazon customer and a rival to Amazon Prime Instant Video service.

Perhaps most worrisome for Amazon is that Google, the one company that many people say can challenge AWS on pure scale, appears to be serious about competing in the Infrastructure-as-a-Service (IaaS) fray.

But back to the list: Bezos rose to the No. 2 spot on HBR’s roster this year, from No. 7 in 2010. According to the authors:

“Under his leadership, the company delivered industry-adjusted shareholder returns of 12,266% and saw its value increase by $111 billion. In recent years the online retailer has expanded aggressively into new segments such as cloud-based computing services, while working to get the most out of the markets it already occupies. Its revenue growth shows no signs of slowing: Sales increased by 40% in 2011.”

The authors acknowledge that Bezos, who prioritizes consumers over shareholders, “vexes” Wall Street at times. (No kidding, take a look at all the “dump Amazon” posts on Seeking Alpha), but that Amazon, the online-retail-giant-now-IT-services-provider, has done well by long-term investors. And, long-term thinking is something Bezos talks up a lot, including last month at the AWS: Reinvent event in Las Vegas, and is also a focus of the HBR Top CEO list.

Another interesting tidbit from this year’s list: Meg Whitman, the embattled CEO of Hewlett-Packard is the top-ranked female CEO, coming in No. 9 out of 100 overall.

Rubinstein, a former Apple (NSDQ: AAPL) executive who played a key role in the development of the iPod and the iPhone, had been working in a fuzzy role within HP’s Personal Systems Group after ceding day-to-day control of the WebOS business unit to Stephen DeWitt in July. Of course, by August the WebOS business itself was put out to pasture following then-CEO Leo Apotheker’s decision to halt development of the Touchpad.

His next destination, however, will be quite interesting. AllThingsD, which first reported the news, said that the timing of his departure was related to a commitment made to HP following the Palm deal in 2010 to stay on for 12 to 24 months.

Apple, it said, remains the single-biggest company in tablets. Almost mirroring 15 million in iPad sales that Apple said it achieved for the quarter, SA says the iPad accounted for 15.4 million all shipments (not sales) in the quarter, compared to 10.5 million shipments of all Android-based tablets.

In terms of market share, that worked out to 57.6 percent for the iPad versus 39.1 percent for all Android tablets. Overall the market saw overall tablet shipments of 27 million units for the quarter, representing growth of 150 percent over the year before. For all of 2011, there were 66.9 million shipments, 260 percent higher than 2010.

The new report (link here) made very little of Microsoft’s tablet effort to date. It only has one percent of the market, and accounted for 400,000 shipments. Just as it had to do with smartphones, Microsoft (NSDQ: MSFT) will effectively be starting from scratch when it launches its next-generation OS, Windows 8, later this year. Rather damningly, the PlayBook from RIM (NSDQ: RIMM) doesn’t make it into the individual rankings, and instead gets lumped into “other” category with possibly a few straggling sales from the now-discontinued TouchPad from HP (NYSE: HPQ) running on WebOS.

Frustratingly, Strategy Analytics does not break out any estimates for how individual Android makers have done, although it does note that Amazon (NSDQ: AMZN), Samsung, and Asus (in that order) are driving volumes among the “dozens” of models on the market at the moment.

However, this does raise another issue: Given the ongoing fragmentation in the market — Amazon’s “forked” version of Android for the seven-inch Kindle Fire, for example, being very different from that of the Honeycomb-version of Android used in the Galaxy 10.1 — and the fact that this fragmentation does not represent much cohesion in terms of services, how useful it is to count all Android tablet shipments in one category, and, more generally, how accurate are those shipment figures when it comes to actual sales?

Enyo, the Javascript-based application framework that WebOS developers used to build their applications, is now available for anyone to examine and modify under the terms of the Apache 2.0 open-source license. HP released an upgraded version of Enyo–which was previously used just for WebOS–that will let developers build Web applications for any browser.

HP said it hopes to release WebOS in its entirety by September. No one is quite sure how much interest there will be in WebOS as an open-source platform, but at least HP will allow some compelling technology developed by the former Palm that never quite found a market to see the light of day.

In an interview with Reuters, Dell’s chief commercial officer Steve Felice does not say whether Dell’s new tablet will continue that Android line, or whether it will be based on Windows 8, the new Windows-based, tablet- and touch-friendly OS that is expected to ship this year.

Regardless, in the parlance of CES’s host town, Dell appears to be putting more chips down for this latest hand. If its earlier Streak effort was low-key and enterprise-focused, this next chapter looks like it will be more high-profile, aimed at consumers and the mass market. “You will see us enter this market in a bigger way toward the end of the year,” he told the news service.

That’s not to say that this means it will be more successful than past efforts, though. As the tablet and smartphone markets have evolved, and there is less emphasis on hardware specifications, there is a growing emphasis on the “ecosystems” that go into the devices, specifically around the services, apps and other content that can be consumed on those devices.

That’s an area where companies like Amazon (NSDQ: AMZN) and Apple (NSDQ: AAPL) have a massive advantage, whereas Dell has yet to demonstrate much leadership.

At least Dell seems to realize this, which is a good start: “When you are talking about PC, people are more focused on the hardware itself,” Felice told Reuters (NYSE: TRI). “When you are talking about the tablet or the smartphone, people are interested in the overall environment its operating in,” he added. “As we have matured in this, we are spending a lot more time in the overall ecosystem.”

In December 2011, Dell stopped selling in the U.S. the seven-inch version of the Streak tablet (pictured). The company never released sales figures, and claims these days that it was an enterprise, not mass-consumer offering, but chances are that it was nevertheless finding it hard to compete against the best-selling iPad from Apple, other Android tablets, and perhaps most importantly, the seven-inch Kindle Fire from Amazon, sold at the margin-busting pricetag of $199.

Currently, Dell is not selling the Streak in other markets like the UK, either, but it has continued to offer Streak tablets in at least one market: China. (Here’s a 10-inch version that seems to have been released only there.)

When Dell pulled back from the market in December, some thought that this was because the company was setting itself up to make a Windows-based tablet. That is the approach likely to be taken by its rival HP (NYSE: HPQ), which itself pulled out of the tablet market last year; and Nokia (NYSE: NOK), which has become very cozy with Microsoft (NSDQ: MSFT) and is now using its Windows Phone OS in its new line of smartphones. If all these (and more) actually do elect to go the Windows 8 route, it could also mean a lot more of the same that we have seen with Android tablets, where a user would be hard-pressed to distinguish one brand from another. That’s another vote in favor of making the services on top of it as unique as possible.

The current CEO of Apple received a base salary of $900,000 as CEO, and on top of that received stock awards that brought his total 2011 compensation package to just under $378 million, according to Apple’s proxy statement filed with the SEC. As one wag put it, that’s equivalent to just over 757,500 iPads (priced at $499). In 2010, Cook received just over $59 million.

Apple compares its executive compensation with that of several other benchmark companies, which include Amazon (NSDQ: AMZN), Google (NSDQ: GOOG), HP (NYSE: HPQ), Microsoft (NSDQ: MSFT) and Qualcomm (NSDQ: QCOM).

But in the case of Cook, “no formula or peer group ‘benchmark’ used in determining the award amount,” the statement notes. The board, consulting with Jobs, determined the amount themselves — a sign that it is outside (higher than?) the norms established by companies similar to Apple.

As my colleague Tom pointed out in his 2012 “look ahead“, Cook will likely be under intense scrutiny in the year ahead as people inevitably ask the question, “Is that what Steve Jobs would have done?” regarding every business decision he makes. However, it bears repeating here that it’s likely Apple’s product roadmap and strategy is likely laid out years ahead of time — meaning 2011 is not on auto-pilot, but neither as freeform as one might assume.

Other executives’ compensation packages were also detailed in the filing. Peter Oppenheimer, the CFO, received $1.4 million in 2011, compared to a bumper year of $29.8 million in 2010. Eddy Cue, SVP of Internet software and services, received just under $53 million. Scott Forstall, SVP of iOS software, got $1.4 million in 2010 (and similar to Oppenheimer, had $29.6 million in 2010). Ronald Johnson, the retail head, had total compensation of $1.4 million ($29.8 million in 2010).

The company also disclosed that it would have its annual shareholder meeting on February 23. At that time, it will vote on its board of directors. The nominees are William V. Campbell, Timothy D. Cook, Millard S. Drexler, Al Gore, Robert A. Iger, Andrea Jung, Arthur D. Levinson, and Ronald D. Sugar. Other items on the agenda include approving the appointment of Ernst & Young as the company’s accountants; an advisory vote on executive compensation; and several shareholder proposals including a “Conflict of Interest Report”, “Shareholder Say on Director Pay”, “Report on Political Contributions and Expenditures”, and “Adopt a Majority Voting Standard for Director Elections”.

The funding underscores how, while Twitter is slowly turning its attention to generating revenue on its social-media platform through advertising and marketing services, it is also still very much picking up huge injections of cash for faster growth.

It also raises the question of whether Twitter may put off thoughts of an IPO for the time being: this latest investment values the company at $10 billion, according to Jack Neele, a fund manager at Robeco Groep NV (via Bloomberg).

The deal follows an $800 million investment taken earlier this year by the Russian group Digital Sky Technologies (DST), and take Twitter’s total investments to just under $1.5 billion.

Not a fly-by-night prince: Kingdom Holdings, in a press release, noted that the deal was the result of several months of negotiations and due diligence on the part of the company.

It could signal a change in strategy for the company, which might be eyeing up other social media brands for further investments. Up to now, it has focused on some key stakes in regional operations, as well as some of the biggest, most established international media and tech properties:

– The company has invested $600 million in shares of News Corporation. Those shares include voting rights and the prince was the subject of some media attention earlier this year when we spoke out in support of the Murdochs during the height of the phone-hacking scandal. That investment has been used as a route to growing out News Corp.’s footprint in the Arabic world.

– Kingdom Holdings and the Prince also have a stake of Time Warner: that came by way of its initial investment of $145 million in Netscape, which subsequently got bought by AOL (NYSE: AOL). The company made further, unspecified investments in Time Warner in subsequent years, and according to its site, has a similar strategy to the one it has taken with News Corp., to partner with Time Warner on regional investments in the Middle East.

– It also, very presciently, acquired five percent of Apple back in 1997, a steal for $115 million. It’s unclear if that stake has increased or decreased but it seems more of a straight rather than strategic investment.

– Other stakes that it has held include those in Motorola (NYSE: MMI), eBay (NSDQ: EBAY) and HP (NYSE: HPQ).

– Regionally, it has a 29.9 percent stake in the publishers Saudi Research and Marketing Group (SRMG), and Rotana Group, a broadcasting JV with News Corp. The Prince also has plans to launch his own Arab news channel, Alarab.

Given Kingdom Holdings’ emphasis on building out regional operations based on strategic stakes, this could kick off an interesting chapter in the international growth of Twitter.

Twitter had already marked itself out during the “Arab spring” revolts as a key route for communicating not only among people on the ground, but also for communicating developments to the outside world.

Twitter’s platform, in its simplest form of exchanging short messages with a group of followers, is highly scalable, working not only on the web and smartphones but on the most basic of mobile handsets. That gives it a lot of potential in developing markets, as well as those that are more advanced.

As part of its bid to reduce TouchPad inventory following its chaotic decision in August to re-evaluate the future of its WebOS group, HP has on several occasions sold TouchPad at steep discounts through retail stores and online. Sunday’s sale was on refurbished tablets, which means HP was definitely scraping the bottom of its inventory in hopes of off-loading as many devices as possible before concentrating on Windows 8 tablets next year.

The devices went quickly, according to several reports, but it was hard to tell exactly how many HP sold. On Friday new CEO Meg Whitman announced that HP would be releasing WebOS as an open-source project, throwing the future of the mobile operating system into limbo. Whitman did say that HP planned to make WebOS tablets in 2013, but it’s not clear whether HP really intends to make a commitment to the software this far in advance without knowing how it will evolve as an open-source project.

Apps for iOS devices, which include the iPhone, iPod Touch and iPad tablet, are now being downloaded in the App Store at a rate of over one billion every month, according to the company.

Today it also gave an update on its newer App Store for Mac computers, and it’s a significantly smaller number and download rate: 100 million “apps” and software downloaded in less than a year, with no specific figure given for the total number of apps, except mention of “thousands” of free and paid apps.

The Mac App store was launched in January last year, so dividing 100 million by eleven months gives an average download rate of just over 9 million downloads per month. That points to how Mac apps might just be a slightly harder sell for the company, which solved a big problem for mobile content when it first launched its app store in 2008.

Given that HP (NYSE: HPQ) is bracing itself for Apple to overtake it in 2012 as the world’s biggest PC maker, that number may well tip going forward, if Apple chooses to make its Mac App Store into the most immediate forum for distributing software for its computers.

At the moment, all App Stores follow the same business model, in which Apple gets a 30 percent stake of all downloads and in-app purchases, while the developer/publisher of the app gets 70 percent. That includes hosting and credit card fees, as well as “marketing” for the app, says Apple.

Last week, Google reported that Android had reached 10 billion app downloads in its first 18 months of operation, with gaming apps accounting for the largest share of those downloads. Android had around 320,000 active applications in the Market as of October 2011.

By one estimate, from analytics firm Mobilewalla (via NY Times), the total number of apps across major app stores (that would also include, for example, the App World from BlackBerry) is now passing one million.

Given how prevalent third-party app stores are on the Android platform, particularly in countries like China but also elsewhere, that’s a remarkable achievement and will probably only grow as Android continues growth as the world’s largest smartphone platform.

New HP CEO Meg Whitman announced the move during an all-hands meeting at HP. Turning WebOS into an open-source project means that third-party developers–both software and hardware–will be able to use the code as the basis for their own projects.

That has the potential to spark renewed interest in the software, given that hardware makers like Samsung and HTC have been looking for places to hedge their bets as the cost of doing business with Android has grown thanks to Apple (NSDQ: AAPL) and Microsoft’s relentless patent assault. HP acquired a strong set of mobile patents along with WebOS when it purchased Palm, and while the company didn’t specifically address the patent issue in its press release, it’s likely that Apple and Microsoft (NSDQ: MSFT) would have a harder time challenging the underlying code, at least compared to how the Android industry has signed license after license with Microsoft.

But the more likely scenario is that WebOS turns into a fragmented mess, something HP promised to try and avoid by “(engaging) the open source community to help define the charter of the open source project under a set of operating principles,” it said in a release. One of those principles will be “good, transparent and inclusive governance to avoid fragmentation,” HP said, but it’s not clear how much authority HP will wield over the project.

For example, Google (NSDQ: GOOG) releases Android code under an open-source license but plays a very strong role overseeing the implementation of Android on the devices that partners build, requiring any device that wants to use the “Android” brand to include a basic set of common code and applications as to minimize fragmentation as much as possible. And obviously, that still doesn’t quite work in the Android ecosystem.

I suppose it’s better for those looking for mobile operating system alternatives that HP chose this route as opposed to shutting down the project entirely, but it’s hard to imagine a scenario in which this creates a competitive alternative to Windows Phone 7 as the most likely candidate for the third slot behind Android and iOS (sorry RIM). If HP couldn’t make it happen on its own, and couldn’t find anyone to buy the group outright in order to set a new course for the software, it’s hard to see how a bunch of separate groups will be able to create anything unified.

That’s because many of those Android partners who are thinking about embracing their own mobile OS destiny are doing so for two reasons: one, because they don’t entirely trust Google’s claim that it will operate Motorola (NYSE: MMI) without any favoritism should it be allowed to purchase the company; and two, because Google doesn’t let them customize Android to the degree that they would like in order to differentiate themselves in the market. So if those hardware makers embrace WebOS, it will be in order to create their own unique experiences, and despite the developer-friendly HTML5 and CSS underpinnings of WebOS, user-interface fragmentation would make it very hard for third-party developers to write WebOS code that would look nice on a variety of handsets.

One thing that could potentially be interesting: someone like Amazon (NSDQ: AMZN) or Facebook might find WebOS to be a more attractive platform over which to layer their own user interface and experience. A company in that position doesn’t care as much about application compatibility because the whole point of such a strategy is to entice users into their own little walled gardens.

All in all, it’s a shame. WebOS brought some very nice ideas to the mobile world, such as elegant application-switching and notifications. But it’s pretty clear that HP now intends to embrace Windows as its mobile platform of the future, and that will force developers to consider Windows tablets in 2012 before taking a flyer on a WebOS that’s being pulled in dozens of different directions.

Updated: In an interview with Techcrunch following the announcement Whitman said that HP planned to make WebOS tablets in 2013, further confusing the issue. Why would HP commit to making a WebOS tablet in 2013 when it has already committed to making a Windows 8 tablet next year?

There’s probably some sense to the notion that by declaring its intent to build WebOS hardware, HP might encourage those thinking about developing for the OS that at least somebody will work on devices to sell to the public. But why then kill the whole project in 2011, only to restart it later? HP is sending very confusing signals about its mobile software strategy, and it’s going to be really weird to see how the company intends to market WebOS and Windows 8 tablets side-by-side, should this statement by Whitman be anything more than a smokescreen to convince people that WebOS isn’t dead.