LGW will be the new BFS i predict, with everyone predicting its failure within a few years.. in the first year Aer Lingus had 750,000 passengers from BFS.. when they had only aimed for 500,000
"And as part of that process we are pleased to announce that we will be adding Tenerife to the schedule from mid-September and increasing services on Rome, Faro, Malaga and Lanzarote during next summer.
source:
Belfast International Airport :: News
if they are increasing those flights then they must be considering adding a 4th base aircraft, as the 3 that are currently based there barely sit on the ground apart from at night.. or i suppose they could reduce the turn-around times like easyJet, but this could be difficult due to the services that all need to get to the plane.. especially when catering, ground ops and the wheelchair assistance usually block each other