Belfast-Heathrow
To me Aer Lingus would be the better option to Heathrow as passengers could make connections with BA flights, but they have to be able to sort the whole Ryanair thing out first. If Heathrow has extremely low slots left, they will not want Ryanair in let me assure you! Ryanair would want to expand in Heathrow, but would never be able to. And anyway I don't think many people would fly out of Heathrow with Ryanair, they fly to about every european destination there is out of Stansted and exactly the same routes out of Luton. Infact if Ryanair got into Heathrow, there would be civil war with BA winning. Do you really think BA are going to give up their long haul slots to a bunch of cheapies? I don't think so!
Back to Belfast, more people would happily choose the connections with BA than the Star Alliance. If bmi continue to loose money on BHD they should pull off the route altogether and that would give way for Aer Lingus to step in from BFS, I mean why try to suffer competition if they can't manage on their own? With so many new direct routes from Aldergrove continuing to grow, the big thing now unfortunately is that people will avoid Heathrow at all costs, and that does play a very big part in the current significant passenger drop. Back years ago when BA and BD both flew to Heathrow, passengers did fly because there was no direct scheduled flights from Aldergrove apart from AMS. Anyway I'm sure something could be worked out to keep LHR flights from Belfast.