an update, just to share my experience with boot camp/gaming on an iMac:
got boot camp installed, XP sp3, and finally NWN2...the iMac with ATI 2400 HD and 2GB ram has no problems at all with the game. Very smooth so far.
Now the tough part...making sure I don't spend too much time playing.
I will soon purchase Elder Scrolls IV: Oblivion, and likely down the road also will try Diablo II, and probably Morrowind as well. That should take care of any free time I might have!