On this note, a recollection system is equivalent to these version control systems, but of course better in every way. There's no particular reason why it should only be possible to recall earlier changes from one session, rather than all sessions, and having such a system in place makes it obvious the VCS is unnecessary. That is, these should be the same things, in the same sense IRC and email should be, because the only distinctions are the queer disjoint features and intent.
I really like this idea by the way (I think it's a rather old one), just forgot to reply.