Since no one has posted this so far, for those of you who have the virtual ticket: Jeremy Feasel let slip a little tidbit in the Gameplay and Systems Deep dive video:
At about 12:38 he mentions an example of a group of trolls that the Alliance will face off against in the new scenarios who are out for vengeance for Vol'jin however, more interestingly for the Horde, there could be a group of worgen called "The Wolfpack" who are out for vengeance for Greymane!
Keep in mind that the context of his demonstration is about flavor RP and AI for those NPCs.