Sounds terrific. Not only do I want to perform limited mirroring (e.g., current packages only, vice all revisions) but then easily update yet another mirror on a disconnected private network.
Updating this disconnected network mirror would require a synchronization operation from my connected mirror, probably conveyed via CD or DVD. To accomplish this, my connected mirror needs to keep state since the last sync-to-disconnected mirror, to be able to determine the diff set.
Anyway, I'm hoping to make this a fairly easy and regular operation. And, of course, apply it to more that just CPAN :)
Off to check out CPAN-mini more closely