You want to know what happened? ok in a nutshell:
they halted production of the barcelona server chips... they stopped selling phenom to retailers, and gave a big discount to system builders (like dell) to take them off their hands... and made a bios patch that disables the part of the cpu where the problem occurs, for a 10-20% average loss of performance.
Finally, the stated that the fixed version would be rigorously tested... which would have made me wonder, except the problem should have been caught anyways in any halfway decent testing. So its pretty obvious the chips were rushed.