WARNING: This post contains spoilers about the upcoming World of Warcraft expansion Cataclysm. Do not read further if you do not wish to be spoiled on major plot points.
Cho'gall's sound files, in Dire Maul, indicate that there are two traitors, an Alliance and a Horde figure, who are working from within to give the Twilight's Hammer Cult a leg-up in recruiting. We can now surmise that those traitors are Archbishop Benedictus, now known as The Black Bishop, for the Alliance and Grand Magister Rommath for the Horde. Sound clips follow: