So far AROS runs hosted on PPC Linux. There is
this bounty for running AROS hosted on OS-X. I believe there is a dev working on a PPC native, but don't quote me on that one.
There is of course, emulation of x86 enviroments that you could run AROS on. With some changes come up via the AROS-64 release, that will make lives easier to port AROS to any platform. Time will tell.
Dammy
TeamAROS