The second ad in the Seinfeld/Gates/Windows campaign launched last night and hit the intertubes shortly after. I must say I like this one better. It's funnier and ties in better (although still loosely) to the actual product they're promoting. Check the ads out here.
Note: It looks like Microsoft is using Flash to run the ads instead of Silverlight, despite the "Get Silverlight" link next to the video. See below.