Just in case you missed it, today Nvidia released all kinds of information on their new GPU. There are tons of previews popping up giving some really impressive benchmarks. If you want to take a look at the card try the following sites, they each have some good indepth articles on this new board...
http://www.firingsquad.com/
http://www.anandtech.com/
http://www.tomshardware.com/
There seems to be a huge leap in performance from the current generation of cards, to the 6800. One can probably expect Ati's R420 to post near this level, or just under. (It's rumored the first board will not perform to the 6800, but the first refresh will). Anyways its exciting to see these kind of jumps in technology.