What I'd expect to see, and being realistic about those expectations, are the 9950 beating / matching the 770 at $399 range and the 9970 in the 499-549 range and slightly behind the 780 (10% +/-). Pending game bundles and aftermarket options they could both end up being better value than Nvidia's offerings.

As you said tajoh, the head room on 28nm has nearly run its course so unless they've made some impressive gains efficiency wise, improvements will likely be akin to the 5870-6970.