Etihad are able to use a full loaded B777-300ER (412 seats) from DUB. The EK B777-300ER range from 354,358,364,427,442 seats so they would be able to operate them from DUB. Remember EK will have the A350 coming over the next few years so thats another option.
I agree with akerosid that EK are needed but I don't think EY will back down as they have a well established service and they are very well know in Ireland. Remember they have a maintenance base here to.
Lufthansa will night stop a A321 from end of October instead of the current A320.
Bmi early morning LHR will now operate at 07.05 with a mix of A319/320. (it was all A320 then all A319).