I wouldn't buy an 6800 just yet. Maybe look into the X800Pro from ATI, it should hit the shelves soon.
I've seen the benchmarks against eachother, and a lotta times the X800 was faster then the 6800.
But then again, nVidia has shown before they can do miracles with driver updates, and I don't mean the shabby tricks they pulled for 3DMark, but real increase.
I'd wait a month or 2 till after their release, then they'll already be a bit cheaper.
Ultima