Delta is also resuming its CRJ service every other hour on BOS-DCA with CRJs. Personally, I think this service will flop unless enough AA FFs can make it work. DL and US dominate the Shuttle market, and they won't be too eager to let AA grab a hold of it. Also, Amtrak is a major player now, when the Acela trains are working. It takes about 2h20 minutes to get from downtown Boston to midtown Manhattan by air (30 minute Boston drive, 20 minute check-in, 1 hour flight, 40 minute New York drive; all at AM rush hour) compared to the Acela, which is 3h30; at times cheaper; and gets you right from downtown Boston to midtown New York.