You know, there are differences between PC and consoles...for me the PC is still the ultimate gaming plattform, especially given its flexibility. I know, the gaming world is turning more and more to consoles, especially with things like Project Natal and such coming up. Still I think that a dedicated Gaming OS could also kind of reanimate the PC gaming world, not that its dead...yet.
The needed support for DirectX of course may be one of the bigges hurdles to overcome...easiest would be if microsoft would create that gaming OS but looking at windows I doubt it would be any good ^^
Premature optimization is the root of all evil. -- D.E. Knuth