Since Virtualmin has not released an updated script installer for this new Drupal version that just came out I just upgraded 2 sites perfectly with Drush. It was the first time I used it and it is extremely awesome! Since you have a Drupal site here yourself you should probably know about it by now anyway but if not I am telling you about it now. And since Virtualmin has an awesome command line you should definitely know about it. Its like a command line for Drupal and can perform updates to the core and modules automatically and tons of other things. I really think it should somehow be integrated with Virtualmin or at least have an installer for it.
It would be cool to have some sort of interface to just click and tell it to backup and update all drupal installs and modules somehow.
Thanks for your time =)