You'll have absolutly no problem whatsoever. The GTX 570 pulls a max of 219 watts. Let's say 240w, just to be safe. Your CPU will pull 130w. If you add everything up, it makes a total of 630w (if you count 150w for the CPU). Add to that your other devices, like fans, HDDs, optical drives...it won't pull a lot. You'll be more than find.
According to our methodology, Thermaltake TR2 RX 750 W cannot deliver its labeled wattage. It burned after one minute delivering 750 W at a room temperature a little bit above 45º C. Thinking that we may have got a defective unit, we asked Thermaltake for another sample, which burned exactly the same way. In both units the component that burned was one of the +12 V rectifiers.