Oh, I really don't see the point in these...
For one thing, I'm utterly confused about which product is the mainstream - 754 or 939. Last I heard, 754 was the mainstream product, 939 was for "enthusiasts", but 754 is to be abandoned sooner or later. That's a mixed message all on its own.
So... if 939 is for enthusiasts, and most enthusiasts don't want "crippled" Semprons (although I love the high clock on my two Sempron 3400s - they're slightly faster for some things than an A64/3200), what the hell are these things doing on the market?
I guess they're a "stepping stone" chip, a bridge for someone who wants to upgrade to, say, an x2 sometime down the road. But who, besides us chronic upgraders, buys upgrade CPUs these days without an upgrade board to go with it?
PCIe support? Well, Soltek makes a PCIe socket 754 board (a nice board, too! About 50% more expensive than the AGP version of the same thing, but that's PCIe for you). Presumably there's nothing stopping anyone else from doing it.
Is there really a market that was crying out for these chips?