I can understand the argument regarding the slow uptake of OS X Steam games, but I can't help thinking hardware plays a small role mainly in relation to more 'hardcore' gamers.

One big advantage a Linux Steam box would have over a Mac is the ability to swap out critical components such as video cards and CPUs.

Even if Valve or others go to the effort of supporting OS X with their latest, whiz-bang AAA title, what's the point if you're on Apple hardware that's limited to a particular GPU that can't be replaced? (with the exception of a super-duper Mac Pro, and even then I can't see it being very easy to just go out and buy a new GTX 650-OMGTHEPIXELS-Edition card and expect it to work the way you would with a 'PC').