I'd say UAE's code could easily be ported to OS X since it has possix APIs.
Maverick, I see you really are considering a Mac
Personally I jumped boat because the Macintosh is the ideal platform for what I do, it's got great power and it looks good. And let's not forget, it's a Motorola Inside machine! :laugh
Fred, clue me up and shout me the names of the best Mac emus around. I know Power64 is THE BEST C64 emu you can get, on any platform. Anything other recommendations?
(btw, get rid of that toilette lid and get a REAL mac