There used to be a mod called "ClassChannels". It's not been updated since about April 07. It added several raid focused channels that most guilds manually but making it automatic. And it used the raid channel to send these msgs on. Here are the channels that got set up.
/dr or /druids
/hu or /hunters
/ma or /mages
/pa or /paladins
/pr or /priests
/ro or /rogues
/sm or /shamans
/wl or /warlocks
/wr or /warriors
there was also role based channels consisting of several classes.
/he or /healers - Druids, Paladins, Priests, Shamans
/ca or /casters - Druids, Hunters, Mages, Paladins, Priests, Shamans, Warlocks
/dps - Hunters, Mages, Rogues, Warlocks, Warriors
Only channels that match your character class are visible by default, but you can enable others
would this be hard to do as a Prat module?