In response to the previous comment, I'd like to mention that DTC does support Xen virtualisation and can control domU creation, administration (e.g. restarts) and OS installs to remote servers.
Look for the help dtc-xen packages to do this work.
Good work. It does however cover too much ground and is not modular enough for my taste. Not close enough to the OS with typical LAMP stack (I do not like giant PHP projects.) Does not appear to support virtualization or large commercial SaaS providers.
Would like to see webcasts or flash movies that demo some of the arcane features (that at least I could not figure out.)