To Clarify, the Cell's SPUs can act as very powerful and flexible stream processors. This due to very high internal bandwidth and very high speed dedicated memory available to each SPU.
AA is not a high compute, low bandwidth task, where cell excels. Quite contrary, AA performance is directly related to chip-memory bandwidth. That's why Xenon has it's high bandwidth eDRAM chip, and higher number of AA samples in most of multiplatforms. As always, you don't know what are you talking about. The problem is that a lot of people believe the things you say, because it suits what they want to believe.