I personally believe the 480 is a good deal. I mean its a Heating nightmare from what i heard but the GTX 570 and 480 have about the same specs. eh its all up to you. If you can afford the 570 get the 570. its not as power demanding. Plus if you ever decide to SLI either one can be run off a 850 watt good brand power supply as long as they have the proper power dongles
That's a tough one, they are basically the same, except the 480 has more memory, which will help in BF3. The 570 is more efficient and significantly quieter. I would have to say, having owned a 480 and a 580, that 480 is a good deal, but be aware of the noise factor. The 480 is louder, the 570 is very quiet.
You might want to consider a GTX 560 Ti 448 core model and overclock it to GTX 570/480 levels.
This is very good advice.
Also, the 480 will achieve within a few % +/- of a GTX 570, so you can just find modern benchmark numbers on that card and then you more or less know how the 480 will do. I'm unaware of any game where there is a large difference between the two performance-wise. Dunno how much overclocking headroom the 480 has but I'd guess not too much.
The 570 is no doubt a better card, it's just not worth $370. IMO the 560ti 448 would be worth the $50 over the GTX 480 - you could overclock it to perform better than the 480/570 and you won't get the power/heat/noise issues.