I run WIn2K in a VM under Linux. The only reason I do so is because I'm testing a communications/control program I'm writing under Linux, and the manager program is proprietary from a another company that only runs under Windows.
So I run that program under windows, and connect to my program running on my host machine over the virtual network between the two, and monitor the whole mess with Ethereal.
VMs are great when you have to run more than one OS--I don't need multiple machines anymore.
Cool.
My programming experience was Microsoft Macro Assembler and DOS (with a little MS Basic thrown in) back in 1987.
Haven't done anything since.