I’ve mentioned it before, but I’ll happily mention it again: When MorphOS gets ported to AMD64, we will not be supporting Macs. AMD64 Macs have all the wrong hardware for that to make any sense. When such a time does come, expect us to support one desktop motherboard (with one family of CPUs and GPUs) and one laptop. We’ll of course make sure it’s hardware that’s actually available one way or another.
MorphOS has undergone a lot of development lately, and the currently available pool of hardware to run it on (G4-based Macs) has grown considerably. The developers have shown they are capable and willing to sustain relatively fast-paced development, which bodes well for the future. Porting it to x86 is the only possible way forward in the long-term.