I placed it in the Yeah it will be DX10, but whether I want it as such I'd say no. Until M$ releases the first service pack, I wouldn't touch Vista.
Currently I'm running a pure Linux setup. No dual boot. Beating my head against the desk forcing a game to run on Linux when I know darn good and well it won't.... Then succeeding in getting it to run(and well mind you).
And for those of you talking about how great the DX10 graphics are, and how dated the DX9 graphics are, Um.... Half Life 2? They haven't really pushed the DX9 engine to its limitations as of yet. So why go to a new DX10. Heck they haven't even pushed OPEN GL to its extent yet.