This is something I don't understand now... Why try to revive the Amiga on another dying architecture (G3 & G4). I don't want to start a flame war or anything but I think maybe more effort should be made to make it on an x86 plateform instead.
First the cost would be lower and parts are more available.
Secondly, compatibility with the older architecture can be achieve via an emulation layer (amiga forever is a prime example). Aros is a step in the right direction but it isn't optimized for the modern chip like the P4 or AMD (using only the -i=386).
Hell, even Apple is leaving the PPC architecture.