On a separate note, I saw over at A.net that Mercer County is starting the process of building a new, larger terminal. I think this is the plan to be a larger (4 or 5 gate) terminal at the south end of the airport, with a parking deck and retail shops (a "Town Center" type arrangement).
I am sure that they will face a stiff court battle from BRRAM and need an environmental impact statement, but I also venture that F9 is dictating this larger terminal in order to continue service after the 5-year lease expires.
It also forces the folks at TTN to ask what type of airport they want to be. I think the answer is that they want to be like HPN (White Plains) - strong service to the tourist destinations (at HPN, that is courtesy of B6), with jet service by legacy/mainline carriers to key hubs.
Both airports also have short runways, although the HPN main runway, at 6548 ft. may allow farther service than can be allowed at TTN's main runway of 6006'.
I'd hate to see TTN lose F9 service, but I suspect this would happen, come 2018, without a new terminal and more parking.