[Muirdach]

I personally wouldn't use something like that, but not really for roleplay reasons (though I agree with the points brought up above). I find that MUDs are a largely disconnected medium, as everyone makes up a character whether they roleplay or not. It helps the players remain anonymous. I wouldn't want other players to hear my voice, nor would I want to hear theirs - because I don't want to "know" the players by default. Perhaps I might become friends with longtime players and communicate with them outside of the game, but I wouldn't want to play a game where it was encouraged/necessary to be that close to other players.

In terms of being an admin, well, it's just another tool that players can use. Close friends are probably likely to call each other and discuss the game anyway. With the vast array of messengers and their availability and ease of use, most likely anyone who wishes to talk about anything, can already. Perhaps it will be a little faster, but I think we just have to accept that outside of the game, players will probably do what they want to, and it is very difficult for admins to prevent this, whether speech or anything else. Making a rule about it will probably discourage some people, but actually going out and trying to stop it will probably not be worth your time.