Facebook’s control: In a post-keynote press conference blogged by Erik Schonfeld, Zuckerberg said Facebook will control the ads, not ad partner Microsoft: “Microsoft (NSDQ: MSFT) is the exclusive third-party provider of IAB standard ads. This is not going to go through Microsoft. We think it is a different kind of advertising.”

Pricing: “The pricing mechanism will be completely auction-based. People can either bid for a CPC or a CPM.”

No opt out: For now, Facebook users cannot opt out of the social ads or turn them off unless they stop posting info. Zuckerberg: “It is an ad-supported service. It is a free service.”

Update:  One addition to the thoughts above: clearly, Facebook is trying to take referrals to new highs—or lows, as the case may be. Also, I can report that Coca-Cola Brand has accepted me as a friend—and several dozen others, many of them fellow members of the media trying out the new feature. Coca-Cola’s activities: caring about me and trying to collect hugs. It’s almost a caricature of an actual person’s profile.

WSJ: Other advertisers include Comcast’s (NSDQ: CMCSA) Fandango, IAC/i’s CollegeHumour.com and eBay. “... Marketers will be able to infuse their ad messages into the activity of Facebook users. For example, a Facebook user who buys a movie ticket, makes travel plans or writes an online restaurant review on a participating Web site will receive a message asking if they want to share their action with their Facebook “friends.” (If the answer is yes, their friends will see the action and an ad like it or not.)

AP: “Among the new features Facebook announced, companies can now embed coding it calls Beacon on outside sites such as eBay (NSDQ: EBAY) Inc., enabling a Facebook user who lists an item for auction, for example, to generate alert messages for Facebook friends, who may then check out the item.”

PBS: Audio of a good NewsHour segment on social advertising with MediaShift columnist Mark Glaser.