Boston is a pheominal market and I've always thought DL would make a move to take it back eventually. It was gifted to JB (by DL) and then abandoned. Part of that was survival at the time, part was the politics there of course, but most was shortsighted leadership teams of the past that the current team inherited.
We've finally grasped that we've got to protect domestic. BOS is one of the best domestic markets in the country, with a healthy international demand as well. Its time to go on the offensive and rebuild what was given away to competitors. I bet AA will also focus on it with renewed efforts too once their merger is fully complete.