I recall Todd Howard mentioning the fact that he disliked doing "alot of little DLC's" for Fallout 3. Got to thinking... what if they're going to work on bigger DLC's but in lesser number? If so I would personally love to see a whole new region or perhaps an "Operation: Anchorage" style DLC, somehow go back in time to the 1E and get to interact with the Dwemer.

Just my bit of ideas