An informative history of the PowerPC architecture can be found here:
This explanation can give some insight into future PowerPC processors and where their development originates from.
The article specifically mentions the GigaProcessor project which many of us recognize from recent posting around the net as the IBM 64-bit PowerPC GPUL (GigaProcessor UltraLite).
It's nice to see some good, Power PC related articles in the midst of a ton of other filth.
I had always wondered the differences between the different flavors of the PPC