Paul, I think Tom's evaluating the broken version because of this quote:
"However, it is clear that Socket AM2 is not just about performance, at least not until the arrival of DDR2-800 in the mainstream market. With current DDR2-667 memory, very little improvement should be expected as the integrated memory controller suffers from relaxed memory timings."
From what we heard about why a new stepping was needed and why AM2 was delayed till June was that the MC needed performance enhancements (source: Charlie/Inq). The above sounds to me like those improvements are not yet available in that engineering sample.
Regards,
Rink