I wouldnt worry too much about Direct X 10 for now as the system it's self won't be available until Vista comes out and you'll probably want to wait a while until you adopt Vista anyway (theres always a "running in" period where early adopters discover massive blunders in the OS which are subsequently patched up or updated via service packs). Also as Vista is still a few months off so are Direct X 10 optimised graphics cards and crucially games that actually take advantage of the new features that Direct X 10 has to offer are even further away.