Just read a thread that Mumble supports 3D audio positioning in Bad Company 2. This means that when you speak to other users in-game via Mumble, your voice will come through their headset from your direction in-game!
...which i thought was rather cool!
:: http://forums.steampowered.com/forums/s ... ?t=1204810
:: http://forums.electronicarts.co.uk/batt ... rocks.html