CrossOver lets Windows apps run on OS X, sans Windows
 

And the Saga continues, http://news.yahoo.com/s/macworld/200...over20060630_0

Wine has been around for a while in Linux community.
An Emulated OS on top of Unix based OS seem to be expensive, in computing terms, consequently slow. I wonder how seemless the transition would be.
Wait a minute. Did it say it will execute native machine code? Cool.
It would be great!! Keep me posted if you see one in action.:)