MorphOS will never port to sam boards. It would require way to much work I think. I think their time is better spent on powerbook/g5 support.
I agree mac ppc hardware is worlds better than any sam board.
If they get g5 support done, that will be awesome, but most g4 macs already run rings around anything sam. I think it was a great idea to port to mac hardware. Its out there, its accessable, its cheap and easy to find...
Amiga os is doomed to die a slow agonizing death when the fastest hardware available is 1ghz (And ridiculous expensive) I don't remember exactly when I had my first 1ghz or faster computer, but it has to be more than 10 years ago.