There are reports that at least the average speed of product mix of the initial Barcelonas will be slower than expected.
I think what needs to be kept in mind is that AMD is in a “damned if they do, damned if they don’t situation.”
At this point in time, from various shreds of evidence, it’s probably safe to assume that the K10 B2 stepping is relatively decent.
It’s probably safe to assume that AMD will want to put its energies into shifting fab production over to B2 rather than any earlier stepping.
It’s also about as obvious that AMD can’t go into full-scale production with it right away, and probably not for some time to come.
However, if AMD said, “We’re going to delay until B2 is ready,” all hell would break loose in the financial world.
So AMD will sell a limited production of B0s and B1s for Barcelonas and maybe the very first Phenoms to get something out there, then try to hang on until the B2s.
For overclockers, the beginning will be B2.