I think a system like this is of most benifit when everyone is in the guild. Since we're on a PvP server, guild chat is an easy way of calling for help, getting advice and just keeping in touch with everyone without doing a lot of channel switching when we're in seperate TS channels.
I do agree with Freak in that I think it's a great idea, but I think it should be on the group leader to label their TS channel in this manner. Otherwise, we'll need a hell of a lot of chat rooms to cover level ranges, zones etc.
Make it so!
P.S. I've got an alt in the level 12-15 range, so when you get into that area, give me a shout and I'd be happy to help you out.