Team Fortress 2 “Coach” Mentoring

http://www.joystiq.com/2011/04/15/team-fortress-2-update-is-devoid-of-hats-full-of-training-and-t/

We thought that enabling player mentoring as part of the interface of your game would really help retention of new players seeking a safe way to learn to play. ┬áThis update doesn’t mention the specifics of the system for coaching players, but the thought of it is promising!
I will be listening for success stories or otherwise.