The new virtualization environment released the same day as the Release Candidate.
I was able to get it installed and running.
UR runs ok in the virtual env.
A little laggy but very usable.
See this post for info about installing the Virtual PC beta.
http://www.winsupersite.com/win7/xp_mode_beta.asp
I'm going to try the XP compatibility tip in the RC.
It's nice to have UR back.