This has been added by the way. There are now 2 channels you can join, a global channel, and a world/local channel.
The commands are as follows:
/channel (alias: ch)
/channel global (alias: g)
/channel world (alias: w, local, l)
You will always be in the global channel by default, ie on server restarts. People in a world channel will always be able to see global messages.
