You have to remember that the catchment area for NCL isn't huge and thus growth will slow down.
easyJet and Jet2 will remain the 2 based LCCs, with perhaps more flights from Ryanair to the likes of Hahn and maybe Stockholm.
Routes that could possibly work are FRA + MUC with Lufthansa (although sectors are long if CRJ operated), VLC and MAD with easyJet, and Eastern European markets with carriers such as Wizz or SkyEurope. Of course, New York with Continental would be a boost for the airport also.
Just have to wait and see what the future holds.