The MUL theory is interesting. Other possibles apart from this and an overclock are whether the 8800GTX has all it's stream processors enabled to aid yields or whether another 32 ( pushing it up to 160 ) can be used in a pinch for a low volume very expensive part. That would assume some built in redundancy which of course is just a wild guess....

You have to assume there is something here or there abouts to counter R600 which has to be quicker to stop the "ho-hum" factor.

Of course the real counter would be to drop the 8800GTX price massively but they ain't going to do that unfortunately I think

Regards

Andy