DX10 is lame:
(1) No game support currently. Maybe another 2 years to become mainstream.

(2) If VISTA don't take off fast enough, DX10 is also pointless. Also, with so many problems with VISTA, i'll prefer to stick to XP as my gaming platform for another 1 or 2 years at least.

(3) VISTA support for Creative sound card is quite lame. Very lame in fact. With no EAX support, all your high-end X-fi and even Audigy card is forced to sound like a normal built-in soundcard. OpenAL support currently is still pretty dodgy and nowhere near the hardware acceleration level of EAX.