If you've got that kind of dough to toss around, sure. But I wouldn't.
While the 8800 is the current 1000 pound gorilla, it's still big and hot and power-hungry. While it is the first DX10 card, DX10 ain't out yet... and neither are decent Vista drivers.
As for me, I'd look at a X1950XTX, a 7900GT, 7900GS, or a 7950GT if I were going for high-end.
My Rig: SABLE
Antec 300 Illusion / Antec EarthWatts EA650 650W / EVGA GTX 760 2GB
AMD FX 8320 x8 Black Edition / Gelid Tranquillo / MSI 970A-G43
Sandisk Ultra Plus 128GB / Samsung 840 120GB / WD Black 750GB / WD Green 1TB / WD Red 3TB
G.SKILL Ripjaws 2x2GB DDR3 1600 - Crucial Ballistix Tracer 2x2GB DDR3 1600
Win7 Ult 64-bit - Func MS3 Mouse - CM Storm QuickFire Rapid Mech Keyboard
R.I.P. Danny L. Trotter
... 14 Nov 1945 - 4 Sept 2009