If anything, I'd say that worrying about DX10 has NV behind ATI in Vista support.
FS has a couple articles comparing XP to Vista performance on ATI Cat 7.1 and also Aeroglass performance hit. ATI seems like they are doing just fine with their current cards in Vista, we shall see how well their DX10 cards do.
http://www.firingsquad.com/hardware/windows_vista_performance_amd_catalyst_7.1/
http://www.firingsquad.com/hardware/windows_vista_aero_glass_performance/
NV on the other hand... http://www.theinquirer.net/default.aspx?article=37314
I'll check those articles out. I actually bought the X2 3800+ processor at Fry's bundled with the exact same MSI board that's in the barebones from Newegg. So, in a couple of months, I'll get another 2 gigs of Corsair XMS, another X2 3800+ and replace the Northwood below.
The only thing different, between the two X2 3800+ systems, besides hard drives and power supplies will be that I'll put a midrange ATI R610 card in one and an 8600 Ultra in the other. That way, I can do my own benchmarks in games that I play often, like Oblivion, HOMM 5 etc.
Everything's arrived but the 7600GS, it should be together within a week (between work and an anime convention this weekend).
It won't beat a C2D, but it's a nice upgrade for me:
Athlon X2 3800+ 65watt
MSI MBOX K9N6SGM-V
2 gigs Corsair XMS
400 gig Seagate SATA II
200 gig Maxtor SATA
MSI 7600GS (to be replaced by an 8600 in April)