I think my answer here is "No, not now, not any more"
PPC would have been a perfectly viable 'future' for the Amiga 10-15 years ago. Nowadays the architecture has all but been abandoned for computers. I believe it still exists in embedded devices, but that's not what an Amiga is :-)
Given the choice of CPUs at the moment, much as I hate to say it, x86 seems to be the only real choice for a high-performance CPU.
Of course, the CPU isn't what makes the Amiga, it's the custom chipsets and ingenuity in the design. I don't care what CPU architecture it uses, so long as it's got some flair that makes it more than just a rebranded PC motherboard.
