New proposal by Cityline:
http://www.washingtonpost.com/wp-dyn...021805721.html
They're proposing 8.5 MSF of development, which is the largest of any project yet (although I'm not sure on specific SQ ftg for the mall projects).
Adding all the major sites together (SAIC, Gergelas, Capitol One, Tysons I, Tysons II, and now Cityline), the total proposed development is now approaching 30 million square feet, which is enormous. Obviously this will be constructed over the next ten + years, but the scale of what's about to happen in Tysons is the closest thing to Dubai the US will see (in terms of boom--obviously not height). It's going vertical, finally!