well i'm going to buy a 480 when they get released for a few reasons:

1) i need a card with around the power of a 5870 (480 by all accounts will be slightly better)
2) i need DX11 for work (dont really care whether I got ATI/nvidia on this one) (I'm a computer graphics lecturer at a university)
3) i run two 1920x1200 screens and ATI **STILL** hasn't sorted out the flickering issue on the second screen! That's completely unacceptable close to 4 months after launch! They may have eyefinity but when the card is in low power mode (ie most of the time) it cant run two screens (my damn 8400gs in my work machine can but obviously its too complicated for the 5870)! I had ordered a 5870 then i read about the issue and cancelled my order and am still waiting for it to be sorted out...

If the 480 launches in the $450~$500 price range I will buy one as there is no other choice, simple as that.