One thing we've seen over the years is where customers make changes to their DNS and either break them, delete records they can't remember or x, y, z.
It would be extremely nice if the backups included a DNS category in that they are backed up at the same time as the other categories and the user can restore the whole zone (or even specific records) to a point back in time.
(similarly, logging shown in the CP of what changes a user makes - so many times in the past we've seen changes are made, user denies doing it and at least in cPanel, the only way to say it was done (but not specific changes) is going through the access log).
