I think I have already sent an email about this to the list, but no reply
on this specific point.
Libvirt is currently capable of storing storage, networks, the only thing
that is really missing is the direct storage of domains. I wonder if a
patch would be accepted that stores defined domains (live) to disk upon
change. Some sort of dumpxml per define/attach/etc. when a domain is
undefined the file is removed.
Stefan