it is no surprise that D3 is faster on the nVidia platform relative to the ATI counterpart with regards the NEW generation of cards, because of the 6800's ability to render in 32x0 rather than 16x1.

i can't recall offhand how the previous generation faired against each other, but it wouldn't surprise me if the 9800 beat the 5900 by a fair margin, because nVidia cocked up the rendering method of that generation of cards.

to sum up:
nVidia wins the current round because it is providing 110% of the generational norm.
nVidia lost the previous round because it provided 90% of the generational norm.
ATI have produced solid products for both generations, but have found the fortunes decided by the competance of their competitor.