So my i7 quad iMac shipped and I'm excited. I don't play a lot of PC games any more but I am hoping that this machine will be powerful enough to run the few games I do want to play well; I will be installing Windows 7 via Boot Camp to allow for some Steam gaming and other stuff. All I ever really play is World of Warcraft, Team Fortress 2, Half-Life 2 and maybe at the top end something like Modern Warfare 2. I hear the 4850 is a pretty decent GPU but not exactly top-end and I certainly don't expect to be running games at the monitor's absurdly high native res (maybe WoW?) but I am wondering what kind of performance to expect and if there is a scaled-down res for 3D gaming that would be best suited for this 27" display. Any thoughts?