While someone needs to put a stick in Intel's ass, I don't believe for a minute that this will remain a cheaper alternative, if AMD starts getting some traction.
Oh, and I didn't see anything about power usage. AMD has always sucked in that regard.
From the Ars Technica article:
IPC is interesting in that it gives a sense of how cores are designed, but workloads aren't constrained by IPC or clock speed per se; they're constrained by thermal and power constraints. And AMD compares very favorably there, too: the Intel chip is a 140W part, so can use about 50 percent more power than the AMD.