Puppet already suppports some level of element copying, but it can only copy files, and that's via a unique client/server setup.

It makes sense to make this a generic feature, so that one host could copy another host's users or cron jobs.

This would definitely require Puppet Authorization.

Update: As of 0.16.0, this feature is available, although it would require a decent amount of development to actually use, at this point. The server functionality is all there, but the client functionality is not, nor is the server loaded by any of the daemons.