Well this review says its not much more performance. I'm upgrading from 939 and actually thinking of getting the $60 AMD Athlon 64 X2 7750 (AM2+) and OC it to at least 3ghz and run 1066 memory. I'd rather save the money for the future rather than have a few extra FPS.
Intel's core i7 really is clearly the better processor with more headroom, but AMD has always had them in the price to performance ratio department. AMD isn't going away and perhaps they can make a better processor like when Athlon 64 came out or at least close the gap and let their price to performance ratio carry them the rest of the way. (http://www.tomshardware.com/reviews/overclock-phenom-ii,2119.html)