There should be an option to use the topic in a channel as the server MOTD. It would be much easier than current solutions (FTPing into the server and editing config files), and probably fairly easy to implement.

Perhaps my other bukkit plugin will intrest you: http://dev.bukkit.org/server-mods/monstermotd/

Using the channels motd will be a hassle because I would need to have an option to specify the channel to use, and have the option to enable/disable this. The config is already confusing enough for most users.