Not only would it mean bad news for Nvidia, but in the very rare event that Nvidia comes out with a card that is better than 5870 AND costs the same, this will be their saving grace and once again put them ahead of the Green...
In my opinion it'll be a card(s) similar to the 5870/5850 but it'll have a wider memory bus than the 5870/5850's 256, maybe it'll be 384 or perhaps even more...
Who knows, but this is very interesting and it seems that Nvidia is running a little late.