Keep believing that..there wont be a lot of difference, but you definitely wont level it. 480 SLI WC maybe, but 470's?..nah.
A 580 is more than just an overclocked 480
5% more, that is all. The rest of the gain is from the 10% overclock.
I have a 10% faster core clock speed over a stock 580GTX which should balance out the 5% gain from the new architecture.
We shall see. I have already posted a lot of my gtx470 SLI results so will wait on somebody with gtx580's in SLI and we'll compare.
Of course, since the gtx580's seem to be able to go past 900Mhz and maybe under water hit 950Mhz without power throttling, that will open up a big lead again by maybe 10 to 20% but mine compared to stock gtx580's, I reckon it will be neck and neck and in some games I'll have them beaten.