Can MacOS be run in a VMWare type environment on Windows?
Yes, OS X can be run in a virtualized environment but the license of OS X client prohibits this use. OS X Server can legally be run in a virtualized environment but only on a Mac OS X host (not under VMWare on Windows, sorry). We use a VMWare Fusion image running OS X 10.5 Server for testing deployments.
The Mac OS X server runs fine on VMWare Fusion but is not officially supported on other VMWare products yet. It would be possible to install it on VMWare Workstation, but I'm not sure how stable it is. See the official guest OS compatibility guide.
Mac OS X client cannot be legally run on any VMWare product.
Yes, I've ran Mac OS in a WMWare virtual environment in Windows. I would say that the exercise is not worth the time. The resulting OS is so massively slow, it's almost unusable. I could actually see the windows slowly drawing on the screen.
And the the VMWare goodies (e.g. drivers) that seamlessly blend the host and guest OSes are missing for Mac OS (as it's not a supported guest, due to it's being forbidden).