Transwede,
NCL is actually XLA third biggest base behind LGW and MAN with the routes continuaully expanding. The -400 is leaving the fleet at the end of the year so next year will probably see at least 1 X -800 and 1 X 757 (Finnair). Not sure what will happen in the winter if FJE do not return - perhaps a year round AY aircraft. Anyone have any news on this?
TCD may also look at NCL again perhaps with a 767 asthey are all part of the same company now.
The 737-400 has actually been performing pretty well as far as I am aware - one tech problem a few weeks back but the other delays have actually been the -400 rescueing other XLA flights with tech a/c being the -800!