I'd say the same.I bet if you broke down the last category a majority of them would be nv 8 series cards.
I have a 4870 - when I was looking for a card back then, that was just the best one in the given price range - if the gtx260 would've been cheaper I'd have taken it, but at least here in Europe that wasn't (isn't usually) the case.
My card before the 4870 was a 8 series card, just because back then it was the other way round - no conspiracy here.
Also the number of people who want the best performance here is quite a bit higher then elsewhere and let's face it, atm there's no real good reason to buy a Nvidia highend card - at least if you could get a 5x card..