It would be great to have a nicer summary of available updates for each jail. One line per available update would be fine, particular if the old and new version could be included in that line.
The ouput in 0.2.0-rc2 is to bloated and hard to read if you have many jails examined in one turn. Best would be something like this:
Jail #1: myhost.mydomain.tld [192.168.0.2]
blah_one-1.5.2 => update available to 1.5.3
blah_two-1.2.3 => no fix available
blubb_one-4.5.6 => update available to 4.5.7
blubb_two-3.4.5 => update available to 3.4.6