Yes, Delta is at a disadvantage vs. VS, BA, AA, and UA, as all four have the valuable LHR slots (which is what the people up front want), while DL has the LGW slots. Yes, to make this route work, Delta will need to provide more feed into the new BOS hub. Right now, we only have connection feed from YUL, PWM, BGR, MYR, and BTV, with YHZ starting in May. By the time the new terminal is built, I see the following routes being served from Boston on Delta:
Connection: JAX (was flown prior to 9/11 with 2x daily CRJ), YYZ, BUF, ALB, SYR, ROC, PIT, ABE, BWI, CMH, CLE (was flown when DL had TSA before ACA).
Mainline: SFO (738/757), SAN (738), SEA (738), LAS (757/767, was flown pre-9/11), PHX (738), FCO (c/s with AZ, getting feed from both sides and Boston's large Italian population), DUB (there are always a lot of people flying BOS-Ireland, both business and leisure), MAN (this is coming straight from Delta), FRA, and CDG (to supplement AF)
However, IF US Airways goes under (which, if their structure does not change, has a good chance to go under, I believe), I feel that Delta and American will come right on in and snap up any left-over pieces, which with US Airways large presence, will enable both carriers to grow more signifigantly into Boston.