While we don't have the official press release yet, 1P Start
does and VE3D was the
first to say it.
Halo 2 for the PC is gold and I was hoping to see co-op play via Windows Live but there doesn't seem to be mention of co-op in the press release. Here's hoping it's in there as that's the way I love to play the game on the Xbox. You'll need Vista to run the game of course.