Gizmodo posted a screen shot of someone supposedly running Mac OS X v10.4.1 via a VMWare session. While I'm hoping this news is true, I'm suspected this is probably a fake screenshot. I've looked through VMWare's web site and can't find anything about upcoming support for the Mac OS X. I suspect this is just a rumor based on the fact that Apple has announced their plans to move to Intel-based processors.
However, the fact that Apple is making this move, it would see feasible that you could write a virtual machine to emulate the Apple specific hardware. It sure would be nice to be able to open up an Mac OS VM to test sites on the Mac. ;)