Personally, how i feel about Vista, DX10 cards, and the G80/R600 cards is as such:
Vista - Meh. Doesn't look promising, plus with the additional resource hog it is, i'm just going to have to learn how to "clean up" another OS of unnecessary crap. That's why i love me some Linux, though i can't completely switch (windows = games).
DX10 - I want to know when it's going to come out. That's it.
G80/R600 cards - If the R600s truly do have 48 pixel shaders on chip, i will never buy an nVidia card. G80, haven't heard much.