I know and accept that heat is an issue, I never said top of the line though. I just want a respectable graphics card. Especially when paired with that huge resolution.
The graphic chips in there are part of ATI's current generation of chips. They have less ram then their desktop counterparts but they are still plenty fast. Coupled with the nice CPUs and ram, I really don't think these chips will have issues playing most games on Windows bootcamp, and as we already know, OpenGL support currently is pretty spotty on a lot of newer games for the mac. Once that is fixed, I see these being very capable gaming machines for casual gamers which Apple knows makes up most of its currently small gaming owners.
My suggestion is to just buy a console if you want to game. Gaming on the 360 or ps3 is so much better then on a computer, unless you want Starcraft II which you should buy.