I'm getting a new pc from scratch. I read that 570 is more than enough to max most games @1900x1200 resolution screen.
Price is pretty equal but...
both of them are perfect cards but the 6970 is better than gtx 570 for the coming games the 6970 will handle heavy DX11 games because of the extra ram.
My vote goes on Radeon side cause of extra ram 2GB vs 1.28GB