It is not currently possible to legally run Mac OS X on a virtualised environment, I say legally as it is practically possible and going to get easier, but I can’t help feeling that this is going to start to hurt Apple in a pretty big way in the next year or so.
Any company with even a medium sized server estate is currently reeling from power prices rises, getting hit twice, once to power the servers and again for the air con to take the heat away. Increasingly virtulisation is becoming a standard part of the IT tool kit, at it’s simplest a quick easy way to replace all those old underused machines sitting the in the data center with a couple of reasonably priced modern machines. This cuts power and cooling costs at the same time as returning valuable data centre real estate. Apple are making great gains in the desktop and laptop markets but I cannot see them achieving the same gains in the server market until they address virtulisation. It’s possible to virtualise other OSs on top of Mac OS X ( Windows, Linux, Solaris…. ) using VMware and Parallels but strangely not Mac OS X.
If Apple want to get Mac OS X adopted in the enterprise, outside of their existing niche markets, they must do something about this either by licenesing OS X to run in VMware or Parallels or by rolling Virtulisation of OS X into OS X. I don’t think they have much time to do this either, waiting for Leopard +1 is going to be too late.