It would be good to figure out key rotation for Dat URL providers since this probably has to be built into the protocol.
Any thoughts on integrating with keybase? I like keybase's model where you have device-specific keys. But this would probably make moving a Dat URL provider to a different machine trickier.
This all assumes that well-known Dat URL's become an important thing to preserve (they are published in papers, etc) even though they are very user-unfriendly, even more than IP addresses.
A naming system on top of them would make key rotation a non-issue (rotate Dat URL's instead) and you could completely replace or remove the history, sort like a git rebase. But that loses other nice properties of the system?
I suppose irrevocability is something we deal with in git repos all the time. Although you can do a rebase locally, once a commit is accepted by a popular project, they're unlikely to let you remove it from history. The review process makes it unlikely that any really embarrassing mistake would be accepted, so this seems ok in practice.