Perhaps this is part of the reason why GK110 is pushed back so far?

I seriously doubt this is only because of NVidia though. TSMC may love NVidia, but no way they'd completely freeze their 28nm process ONLY because of them if they had plenty of business from AMD... Although, they may still be mad that AMD tried to only do cayman on 32nm (which is why TSMC cancelled 32nm altogether).

If it was having major yield problems though, maybe that's part of the reason AMD were pricing so high.