I wouldn't count AMD out just yet. From what little I've seen from my new AM3 Phenom II X4 955 (3.2GHz quad core) system there's plenty of life left in the chip. I'm pretty sure 4GHz could be an achievable standard clock speed (I've briefly changed the multiplier on mine to run at 4GHz at the standard core voltage with no problems), and the current range supports dual channel DDR3 which the core 2 range does not. In fact, from what it says on that website above it looks like the AM3 Phenom II is actually going to be very similar to the Lynnfield in terms of performance.
I would not be surprised to find a Phenom III range appear in the not too distant future running higher clock speeds than the Phenom II, coming complete with support for triple channel DDR3, larger on chip caches and a more sophistcated memory controller switching automatically between ganged and unganged mode depending on the core loadings. This is pure speculation and is most definitely not based around anything I have seen or heard, but its where I would be headed if I were AMD and didn't have viable competetors to the core i7 and core i9 nearly ready. But, for all I know AMD might well have competetors for these chips in the wings and ready to go very soon.