Well if Mac was a "good guest", it would run happily in VMWare as a guest Operating Sytem, in which case you could choose whatever "big box" you wanted
from any supplier - and still have available all those operating systems you wanted, via VMWare.
While the rest of the Operating System world is opening up, Apple is still trying to keep their doors locked. Sure there is a VMWare tool for running other Operating Systems in OSX - but not the other way around. It's just another exmaple of Vendor lock-in from Mr Jobs. I suppose he is still busy trying to get Java 1.6 running on Leopard, however since they managed to take the ZFS filesystem technology from Sun for use in Leopard, I would have expected that they also could have got the latest Java version running
It would have to be a very bad day indeed in the computing world before I bought a Mac just so I could run other operating systems