I personally think that a PPC mac port is the only chance os4 has at making any kind of market presence. Don't get me wrong I'm not one of the dreamers who believe the amiga will be anything other than a hobby OS ever again.
What are the reasons that the port was binned?
One of which is probably piracy, that is simple enough to overcome as all "new" macs (g3 blue and white onwards) support usb in the open firmware so it would be simple enough to sell os4 with a usb dongle which would replace the need for the a1's uboot rom.
Another is probably Ainc cant get a premium on custom hardware, well the prices they have specified on the ACK machine probably dont have very high margins in them anyway.
I can personally lay my hands on a load of G4 500 full spec macs right now for under £50 each plus i got a 1.5Ghz ppc mini sat on my desk that would make a great OS4 machine.
So come on A.inc do something for once and licence this port and you never know you might even make some money, I know I'd be ordering several copies.
Gaz
http://www.lincsamiga.org.uk