Well, with Bitmain coming out today and stating that the anticipated hashing rate of 478GH/s caused problems, I doubt there will be much success in over clocking these at all - at least batch 1/2/3.
I'm actually going to go the other route, as philipma1957 alluded to. If these can be under clocked to get 400GH/s at about 275W, I'll throw 4 of them on and EVGA G2 1300. Now, with Bitmain also offering coupons/discounts for those of us that ordered the first batch, I'll most likely grab a few more depending on the under clocking results.
yeah 400gh in the 250-275 watts range make them very quiet and cool. I have 2 evga 1300's I my end up with 6 of them 3 in my home and 3 at my friends office.
it would be 2.4th along with the 1th hosted in china. gives me 3.4th push 0.4th at bitsolo.net and the rest at btcguild and bitminter.