The PowerPC has the same energy-saving attributes as the Power4 but uses only one central processing unit, not two.
From Forbes.com news item about IBM PPC970.
The OS + apps should be able to use both cores inside the CPU
If the new PPC is single core, may be this means one less problem. Though, they still need to rewrite apps and systems.
About 64bit CPU: If these become mainstream, then those new experimental (open-source/GPL) OS's could see a new boom. I'm talking about some SASOS (Single address space OS) that are being designed and developed in small groups on rare machines. They try to implement some weird but interesting ideas that take profit of huge 64 bit addressing. x86-64 and this PPC970 could be an inexpensive way to boost those developments.
