site has a 7800 GTX. They scored 7703 in 3D Mark '05.
Now, this wouldn't be so impressive, considering that it will likely cost twice as much as a 6800 GT, and an SLi setup with two of those gives a score of around 8500.
It will be interesting to see how things play out though. I don't even think that the 7800 GTX is considered the Ultra, so I would assume the Ultra version could hit 9000 - 10000. Not that we should go by a crummy benchmark anyway..