Does this mean MightySites supports administration of multiple Joomla! versions (v2.5 and v3.1) from a single 'master' installation?

I'm most interested in using MightySites to aggregate one master site and any number of subdomain slave sites used primarily for testing various templates and extensions before they are deployed in production sites. Ultimately, I'd love to be able to use the master site to demo the slave sites -- mu...