I agree that there's still considerable opportunity on s/h; Mannion has already mentioned Russia and Greece. However, I have to say I'm very uneasy about the idea of developing another hub in Europe; to me, it's inviting disaster. EI needs to consolidate its position at its home base; establishing a new base in Europe only invites other carriers - particularly low cost carriers - to go in and compete against it; it has to get itself established and it has to face all the costs associated with a new base - crews, support staff etc ... all money far better (and more urgently?) spent at home.
There are so many stories in business - not just aviation - of companies which made a mess of things because they lost focus. In the old days, as a state owned company, EI could rely upon the state to pull it out of trouble; in the new, privatised environment, there's no safety net. Aer Lingus's focus needs to be on developing short haul and particularly, long haul. It needs to develop an effective hub at DUB (although opinion is divided on whether the day of hubs as passed). I'd much rather see EI investing the money it might spend on building a Eurohub on boosting its long haul network, its service product and other "home" areas, rather than opening up a whole new area for other carriers to attack it on. It doesn't need to do this. Why be diverted from where the important battle really is?