It's still going to be slow isnt it? I mean, you'r not going to be able to run you'r even near what they're support to run at. That is, i assume its slow. Look at 68k emulation, thats not too bad, but thats mainly because everyone has low expectations because the 68k CPU's are very slow compared to x86 CPU but the PPC is on par basicly.
I'd be surprised if you could run MacOSX at a good speed!