I reckon terminal development will only come once we have more legacy carriers at BFS, something that seems stubbornly difficult to achieve. Legacy carriers will pay the higher landing fees that justify the lounge facilities and airbridges they want for their customers. If we had Air France or Lufthansa offering short-haul, and perhaps a US carrier (again), added to the VS service to MCO, maybe we'd be on the way. The long-haul pier is crying out for rebuilding...the rest of the airport is a bit messy, but generally in decent order. If we had those airlines, then a long-haul rebuild could be part of a bigger phased effort.
However, while EZY and FR dominate traffic, it's hard to see much in the way of development coming (sadly).