What I find funny is people automatically assuming Nvidia will beat it, I'm not remotely convinced they will.
The more we here about it the more I think its moved to clusters of SP's, albeit not as significantly as ATi, the last thread had some "info" on it mentioning 16 real cores and 32 logical cores, but that was talking about the lowest end parts, with the high end having 512 "cores" but not listed as logical of physical. its a bad translation and not accurate and nothing to prove anything. But personally I think they've moved from Single SP units, to double SP units, which frankly should be far easier to program for than a full on 5 unit cluster as ATi have. Which would mean 512 logical cores(2 sp's per physical SP unit, of which there would only be 256). Which would give it double the raw horsepower in best case scenario, but not always. The same way ATi's best case scenario in a 4870 blows away a GTX280, but it simply can't provide best case all the time.
THe fact that Nvidia had a huge core and are moving to a horrible process, have higher clock speeds making that issue worse, they need to shrink it and making clusters, as AMD have make it far far lighter on core logic per SP, meaning dramatic saving of transistors.
I simply can't see how they can't have gone this way, as if they double the SP's as suggested, with all the same core logic aswell as add DX11 functionality they will be increasing core size the same as ATi have, which from a circa 500mm^2 core would be, suicide on price.
The fact is, yields are abysmal, size would be ridiculous if it was anywhere from 480-512 real single SP's in a similar architechture and it would be £400-500 just to break even. I can't see that happening in any way shape or form. Considering Nvidia have almost certainly had to drastically change their architechture, you can't really guess at its performance at all.
Frankly whatever Nvidia can provide, I can't see it being close to sub £400, and considering it won't be 2x5850's for the same price, I can't see it being competitive at any level.