So, the 6950 from AMD cam in at about the same level as a 570 (rounding down, but whatever). The 570->670->770 would be a 44% increase. For that 44% increase in performance I'd be looking at a price increase of about 100% (late adoption of the 6950, coupled with an assumed tag at $400 for the 770).
Anyone else staving off the urge to buy another round of graphics cards? A 72.8% performance increase might only cost 120% more.
Let's look at this realistically, AMD and Nvidea are treading water. Giving these cards the BS factor that these "benchmarks" need, you're still not looking at a good reason to buy them unless you've got either a 4xx or 5xxx series card still inside your rig.
It hurts me to say this, but AMD and Nvidea please slow the releases down. Get us better price points, with substantial performance gains. I'd love to have the highest end graphics to play with, but unless I discover oil in the back yard I can't afford anything but an investment in every third generation of cards if you keep up with this. Heck, a pair of previous generation cards in either crossfire of SLI costs less and delivers better performance than what you are offering as your high end cards.