Really does not matter to me if there is no DX 10, we all remember Crysis with the DX10 hype ...ooops could be reproduced using DX9 (not all but enough for the visual dif. to be minimal)
Anyways, IMO win7 is worth the upgrade. My initial benchmarks & gaming exprerience with 7 has been way better than with Vista x64 & I've also noticed an improvement over XP.
Some benchmarks in 7 where probably influenced by drivers because the RE5 benchmark resuls went from 54fps in vista x64 to 91fps in win7?! To much of a jump to be the OS IMO.
As for gaming it just feels alot smoother can't say there is an increase in fps but the feel especially in COD4 is way better.
Anyways that is my 2cents..nothing scientific just general observations about 7.
Anyone who upgrades smartly can be graphics wh@re nowdays! According to the latest buyers guids I have a mid range machine (1000 to 1100 no monitor) but it runs evertything maxed out 2x AA 16X AF @ 2560x1600. No I7 here or even DDR3 but I do run SLI.