580 is a better buy than 5970 in nearly every way, but its main competitor won't be 5970, it will be 6970...

I sold my 5970 one day before the 6870's came out because I thought its second hand prices would fall dramatically (which it did). As much as I want to buy a high end card as soon as possible, there is no way I am buying a 580 before I also see what AMD has to offer in this price range.