Okay, i'll comment on this thingy.
I installed it a couple of days ago, and started to hack around with it, it is possible to install OSX ofcourse, but the speed is dog slow :-)
The Gfx and I/O performence of the emulation isn't that bad at all, but the CPU Core is lacking.
The CPU core exists atm in 2 versions, a purely interpreting core, and a Just In Time Compiler (think Amithlon's m68k core).
What most people assume to be such a big problem is the amount of registers the PPC has, this actually isn't THAT big of a problem at all, in interpretive mode it will indeed waste quite a bit of cycles (less then you might assume, as the 'registers' stay in L1 Data cache) on JIT this is only a problem when running a piece of code for the first time, after that the code will get ranslated to native x86 code (the "Just in time COMPILATION" thingy, right ? ;-) *grin* )
/ I think i just hitted a Post-lenght barrier /