Original Comment by: Slartibartfast
On second thought:
There is a slight chance that "optimized" means something if the game is directx 10 compatible. I believe DX10 is under development and I know for certain that XP is not going to support DX10. DX10 looks to be a serious upgrade, but the thing is, no current videocard supports it. So for said "optimizations" to be true, the following would have to be true: the software can make use of DX10, DX10 is even out, and you have the latest and greatest videocard because everything else is not DX10 compatible. So to get any sort of theoretical optimization out of it, you would need to not only cough up the cash for Vista (~$200) but also for a new DX10 capable videocard (~$500).