I ran Win2k under VMWare when Win2k first came out, but not in a production environment. Anyway, it ran quite well. I never had any problems with it at all. They've come out with several newer VMWare releases since then, and I can't imagine that stability has worsened. The only problem I can think of is that I don't know of a way right offhand to get it to run on bootup, as I don't know if VMWare will run without a display. You might have to run an Xvfb for VMWare to display in.

In addition, I ran VNC server on the Win2k machine and never had any problems with that, either.