My unsubstantiated guess is that the original model of linking under or unserved destinations with London will be revived using the Sukhoi jets to destinations too far for the ATR, mixed in with a couple of reliable holiday favourites.
Turin is one such example that used to have frequent morning and evening flights but now seems to be down to Ryanair and Blue Air at random times. If they overnighted the aircraft there I'm sure it could do pretty well. Leipzig has only a Ryanair flight. Dresden has nothing. Maribor proved to do just fine, the sort of numbers and fares Adria were getting could be attractive. Kristiansand has got the sort of numbers you would need for a Sukhoi the past, Norwegian tried it for a bit but couldn't fill a 737 and Flynonstop went bankrupt. And then are places like Malta, Dubrovnik and Corfu that EZY don't fly to from SEN.