They have had full speed PPC / Mac emulators for many many years now. I actually had one running in windows98 years ago. Although they have issues with hardware accelerated graphics.
Are you sure? they have been able to emulate the 68k cpu for ages on pcs with an x86 architecture, so mac os 8 and below have been possible to emulate for a long time, but this is the first one i know of that is able to run mac osx or linux for the power pc
I never tried OSX with them, because OSX wasnt arround, but I am sure that those emulators have OSX versions by now, they were nice full speed Mac emulators, MUCH faster than VMWare is, and this was years ago...