News-flash: HD6970 isn't the high end card in AMD's line-up. There is a HD6990 coming up and nVidia doesn't have a counter, no matter how much you'd want a GTX570x2 to appear.

You have no idea what the price for both GTX560 and HD6950 1GB is going to be, but you specualte wildly and unconstrained. They might end up above what is called "mainstream".

You argue 2GB card versions are pointless, but then say there will be a vacuum for nVidia to fill? 2GB makes a lot of sense from an OpenCL/CUDA perspective and for Eyefinity. Oh wait, nVidia doesn't do Eyefinity with one card. So who's got a bigger potential market for 2GB cards?? I won't even mention the obvious fact, that 2GB is being future-proof.