At work we use VMWare workstation running under Windows XP hosting i386 
NetBSD (At home I use VMWare player on Windows XP 32 bit hosting hosted 
NetBSD amd64).

We have been using this setup for a few years and have had no serious 
issues. Something that may be helpful is a set of tools found at:

http://chitchat.at.infoseek.co.jp/vmware/index.html

These are released under an open source liscence (I have not checked to 
see if they are in pkgsrc) and provide similar functionality to the 
vmware tools. Since I had problems with ntpd keeping the clock in sync 
(It fails to update the time when it varies too much from the time 
server which occurs after pausing the virtual machine) I setup a cron 
job that uses the above tools to sync the time with my host windows 
machine.

Anyhow, I hope that can help a little.

Brendon.