Next Generation is reporting that DirectX 10 will only be released for Windows Vista
. Those of us puttering along with XP will have to make do with 9. From the article: "The exclusivity of DirectX 10 means that in order to enjoy the high-end features of next-generation GPUs, gamers will need to adopt Vista. Some end users are upset with Microsoft, as the move effectively forces gamers to buy Vista if they do intend to remain serious about cutting-edge PC gaming."
It may even be worth it for titles like Crysis.