nVidia doesn't have to beat ATi with more than ~10-20% all over the line up to make a success out of Fermi. Don't forget that the 5870 with that hefting price tag (comperad to 5850), is only ~10-20% better than 5850.

If GTX 480 is ~10-20% better than 5870 then nVidia has a winner, for sure, even after 6 mounts. Unless ATi can release a new/refresh card to match/beat it at the launch time.