Love the concept. I came looking for a Moodle VM, but as far as I can see, you are only shipping Moodle 1.8? As far as I know, most Moodle installations have moved on to 1.9 and are eagerly awaiting 2.0. There are so many security and usability issues with 1.8, that the general advice seems to be to go for 1.9 at present (it was released in March 2008, so is pretty stable now). I'm not sure why moodle.org still has 1.8 for download even - I guess some people can't have upgraded.
Anyway, it would be really great to have a Moodle applicance with Modle 1.9 on it, and I'd guess that 's what most moodle admins would be wanting. Although the full 2.0 is not out yet, doing a VM with the current 2.0 snapshot could generate a lot of interest in the moodle world too.