AA has had very high loads ORD-LHR-DUB -- lots of people avoiding the EI ORD-DUB service for whatever reason. The timing of the AA flight also makes it more convenient and more a supplement than a competitor to EI. It might pick off some BD traffic as well. At first I thought it was an attack on EI but it looks like the market has plenty of traffic and it is AA selecting a route based on probable yield. The BOS-SNN route is also under-served, I've been told, which seems surprising but AA has been very good at evaluating routes. The very high disposable incomes currently in Ireland (maybe the richest country in Europe today per capita!) has led to huge increase in travel from Ireland as well as the business flying that goes with a booming economy. Who would have guessed that Ireland would evolve this way in the past decade? A massive beneficiary from joining the EU.