We have actually been using the Virtualmin GPL version for years. Loved it then. Love it now.
About 6 months ago we setup a few new servers to begin a migration process with our clients to get them off of the previous hosting system and onto some new hardware and features. During this process we found that many people were interested in VM hosting and proceeded to configure XEN3 for some testing before we offered it to our clients. We have since found some flaws and found some fixes... you know the story. Overall we are pretty happy with using it as a solution for certain client needs (particularly those savvy enough to use the shell without us granting them open access to a system where others are hosting as well.) Thus we established that XEN is a pretty good fit to our clients' needs.
Seeing that Virtualmin is developing a management software for the VM instances elated me. The problem is that all I can find on the project is that it is "coming soon" and that if you want to test it, contact Joe (no email given.) So... I thought, maybe a forum post for project updates would be handy for those other people who may also be interested in the project, testing it, buying it, etc. This is not a solicitation for the beta, just a request to learn more.
Anyway, not a deep question or anything, just a place to possibly sway Joe into posting some project updates and projected release dates. :-)