There’s very little information about the up and coming Marvel Universe Online, co-developed by Microsoft and Cryptic Studios.
There’s a short blurb about it at the Cryptic Studios website. The wikipedia entry also states that the game is being developed for both the XBox 360 and PC/Windows Vista (of course, it’s Microsoft). Release date is a “To Be Announced” 2008.
Perhaps Mr. Gates wants to have something to augment the huge windfall of Halo 3.