I work for MWAA and might have some insight into what's going on as far as development plans at IAD. Shoot me questions in replies below and I'll see if I can give you all some answers.

I recently read an internal report that the earliest any expected movement on C/D would be sometime around 2017. This is right when DCMP Phase II is supposed to finish up (unrelated) and what their talks with UAL have yielded. Back in 2011 MWAA formed a new business team exclusively to talk to UAL about making C/D move forward. They also have plans for the first phase of Tier III (Concourses E/F) to be built soon, possibly at the same time as C/D to give some operational flexibility while the move is going on. There is already a shell of a station for the APM east of the new ATC tower. Concourses E/F would be built in two phases, with the phase east of the ATC tower having piers branching off the south of it to facilitate regional jet activity. There would also be room to install sterile corridors on the north side of it.

Like I said, shoot me questions and hopefully I can give you all some insight.

Oh by the way, it's my first post here. Howdy y'all!