Well I've tried Vista on 3 computers, a regular PC, a MacBook Pro and a Mac Pro, it worked fine in all of them and Vista got the wireless in my MBP working right away, in fact it got everything working right away minus sound, same for the Mac Pro and the regular PC, everything worked fine minus sound (for the regular PC a simple trip to windws update fixed it).
I'm liking Vista very much and yes I've done some limited gaming, I installed The Sims 2 and all expansions, all recognized well in the games explorer and I didn't notice any performance or compatiblity problems over XP, I'm using the crappy beta drivers though, can't wait till ATI releases 7.1 for Vista...
As a sidenote, Diablo II worked perfectly , games explorer boxart and rating and all.