Nice to see this conversation continuing.
Obviously, our future systems will all be multi core.
My Macs have been at least dual core since I upgraded my Quicksilver to 1 GHz.

While single core PPC processors are still available, from a price perspective it does not make sense to use them.

Since Andreas first mentioned the T1042, this has seems the ideal processor to focus on.
Not surprisingly, Andreas was also one of the first people to mention the e5500 core.

If we could find a good carrier board that would just require a CPU card, the T1042 could help us realize a low cost PPC platform.