The motd is now part of the redbrick-motd package. The package includes
a cron script to reset it via cron.daily, and an init script to reset it on boot. It also includes
/etc/motd.* files needed for the motd, and
/etc/motd.dat are marked as conffiles in the package, and won't be overwritten, for obvious reasons.
I planned to do this sometime, but never quite got around to it :(
Anyway, what i'd do is to keep all the current stuff, but to put up a php/mysql thing to enter motd items. The cron scripts could then generate motd.dat by reading directly from the database. If the database isn't accessable then the script could just fail, leaving the old motd.dat in place, and thus not making a mess.