i think AMD didn't wanted go to 2GB, not really usefull in most case. If you don't have at least 3x 24", or play crysis in ultra, on 30" with AA8x, there is no real need.

Actual games, don't use 512Mo of textures.

And if they want go to a 384bits bus in next gen ( they won't go in 512bits, we don't need it before a very long time ), they'll sell 1.5go Vram video card, and sold before 2GB. So This could become a problem for the "upgrade" path.

1GB and special 2GB eyefinity 6 is a good choice.

The thing i hope, is AMD will sell the first day in same time, 2GB special eyefinity and 1GB normal edition and will be fully available in sellers. It was a problem with old 5870 six edition.

and i would like to see cayman pro 2GB edition too.

It would be a real smarter choice.