MassPort will probably be under much pressure to relax their Terminal E obcession with international flights... in the end, it will hurt their business (MassPort's) and the popularity of using Logan as a transfer point in both directions. The idea behind alliances is to get off your AF or AZ flight from Europe, and board a DL or DL connection flight right after clearing Customs and Immigration, like ATL,JFK or CVG... not to have to make the hike from E to A.
AeroMexico just started BOS-MEX daily service on Feb 13... another opportunity for codeshare for both DL and AM. Again, it works best if all could be in the new Terminal A.