I'm curious as to why that isn't more common, although you get a similar compatibility issue with your choice of vmware, xen or virtualbox; and there is some overhead; but yes, it sounds like a good idea to me.
http://www.rpath.org/ does something like that for server side software, and I know vmware supports that model.
http://www.rpath.org/ does something like that for server side software, and I know vmware supports that model.