I've been pondering the URL-bug [1] recently. Today, I found some old docs by Sir Time-Berners Lee (the brain behind the Web), and in the midst of all of them, I found this little snippet:
"I think that naming a node should be optional: perhaps by default the system could provide a number which can be used instead of a name.The system should certainly support the naming of nodes, and access by name." - Tim-Berners Lee on Navigation.
It's basically what MovableType does. MT creates a number based on the database id of the post you're creating, and uses it unless you've asked it to use "pretty" URL's.
While this doesn't solve the problem, at least it gives everything a name. I guess if the users realizes they didn't give a resource a name (so it's an ugly, forgettable number) and therefor wants to change it, they could, but rather than actually changing the name it would *move* the resource and leave a redirect page in its place.
That's where some of TBL's notes on versioning would be handy to review.
[1] URL-bug: If everything in the Semantic Web needs a URL (or URI), and "cool" URL's never changes, then what do I call my URL to keep it "safe" from the future?