Do I really need to spell it out for you? Kentsfield has a 10% IPC advantage over Phenom, Yorkfield has a 15% advantage.
Now, you tell me, what you think AMD needs in order to compete with 2.5 / 2.66GHz 45nm C2Qs.
They certainly dont need the high end to compete well. As lond as they acn keep price/performance competitive on the main stream they'll be able to do reasonably well. They may not be able to take the crown, but they can compete on the main stream.
Do I really need to spell it out for you? The boat floats both ways.