Thanks for that reply, and you've put a lot of thought and possible problems in to it.
It shouldn't be emulation as it is WinUAE but it should be emulation in same way that Fusion works on Classic Amigas or how MOL works under PPC Linux. You only emulate what is missing. There is no reason to emulate a PowerPC CPU when you have one available. Therefore the PPC emulation would be quite quick.
I agree with you on this 100% UAE would be slow. But we'd need a good emulator, look how many AGA only games/utilities are out there. As you say, there's a lot of problems that could'nt be brought foreward untill it was actually taken on, but I think it would be a very viable undertaking, so many Amiga users would benefit, as a lot of us allready have G3 PowerMacs. :-)