A heavy Saturday coming up for CBSSports.com, including streaming the Southeastern Conference (SEC) championship between unbeaten Alabama and would-be giant-killer Florida. (Alabama is ranked #1 across the polls; Florida is ranked #2 by AP.) The game (4 p.m., ET)  is the culmination of the network’s first season of a new deal with the SEC that allows full live streaming online and on CBS (NYSE: CBS) Sports Mobile for those with access to MediaFlo. AT&T (NYSE: T) is sponsoring the webcast, which CBS is pitching as “the biggest football game ever broadcast simultaneously on TV, the Internet and mobile.” Of course, mega-fans will be watching on mega-screens and it’s a weekend, traditionally lower in traffic for digital media, so the biggest game may not add up to a lot when it comes to online and mobile viewing. 

That’s the marquee match but Microsoft (NSDQ: MSFT) is a sidelines player in another CBSSports.com game Saturday—it’s sponsoring a live webcast of the 109th Army-Navy football classic (noon ET). The sponsorship includes producing the game with its Silverlight video platform. It’s the first time CBSSorts.com has used Silverlight for a free football game but the Microsoft video player is used for the CBS College Sports Network subscription package. Is it a one off or a tryout for something bigger when it comes to live streaming? Given the recent high-profile loss of Major League Baseball Advanced Media to Adobe (NSDQ: ADBE) Flash, Microsoft could use the boost of providing the player for March Madness on Demand.