So I plan on upgrading to a new Intel mac soon and plan on installing Bootcamp on it for games ASAP. (BTW, Bootcamp now supports 64 bit!)
I used to have a gaming PC back in 2001-2003 and ran XP fine, but with Vista I wanted to see what I could dig up in the way of recent reviews and found a nice write up over at ZD net.
XP SP2 vs. Vista RTM vs. Vista SP1: Gaming benchmark | Hardware 2.0 | ZDNet.com
I wish it delved into the difference between 64 and 32 bit, but all in all Vista still looks like a dog.