My 6950s are here!
I don't have my new mobo yet so I just popped one of them in, replacing my 2GB 5870.
I got the Sapphire "Dirt 3" edition 2GB 6950s which come with a dual bios switch. If you flick the switch to the non-factory setting it unlocks the extra shaders from 1408 to the full 1536 that are available on the 6970. Then you go into the cool Sapphire TriXX utility and raise the core and memory clock speeds from 800/1250 to the 880/1375 from the 6970... voila... you've got a 6970 but spent $100 less!
So far this thing blows the 5870 out of the water. I can run medium-high settings (with minimal AA) across 5760x1080 resolution. It's going to be nice once I CrossFireX both of the cards. I should be able comfortably run High-Ultra settings.