When one considers how dungeons and heroic dungeons will work in Cataclysm, one of the first elements to consider is the way that dungeons have functioned since World of Warcraft's release. I find it illuminating to consider that one of the most complained-about aspects of dungeon running in Wrath of the Lich King seems to my eyes to be a consequence of a successful series of design changes.
We've all heard the complaints about groups treating the dungeons and heroics of the Wrath era as chores, five- to 15-minute frenzied runs through the place, annihilating everything in the path of five silent, grim harbingers of death. No nuance, no subtlety, and no strategy. Crowd control? Crowds are controlled by their own grim, horrible demises. When considered in this light, these dungeons seem less like adventures and more like unfortunate victims of beings who invade and despoil.
However, the reason for this is fairly simple. In Wrath, dungeons have been wildly successful at two very difficult tasks.