Andreas, I didn't respond immediately to this because I wanted to avoid a protracted argument over opinions.
We both know the PPE core of the Cell is a little weak, but that will not be a problem with its successors (which will feature out of order execution pipelines).
While I have given up on the idea of asymmetrical multi-core processors or the SPEs, their value and real world performance potential is debatable. And whether you consider the additional programming considerations necessary to harness them "more invilved" or very significant, it does require consideration.
This is where Microsoft's use of multiple identical cores on the Xenon may make more sense than the odd combination used in the Cell. Code is uniform requires no more consideration for the architecture then it be threaded.

I don't mean to slight minator or any of the other Cell "experts" (although I have given you my definition for "expert"). But, while I respect IBM's engineering prowess, I'm not sure they've proven their case on the utility of this approach.