8900 GTX, eh?
Heh, I can't wait for the R600. Unconfirmed early benchmarks show that it already beats the 8800 GTX. The awesome thing? It's downclocked from the actual target clock speed and it's using GDDR3, not GDDR4.
Early revisions of the R600 will use GDDR3 (January), but later revisions will use GDDR4 (March-May).