US flights
I agree that market forces will eventually decide what Irish Airports will have US flights.
Shannon has 60 years of history and brand recognition behind it so CO and DL probably feel its a safer bet than Cork.
As for Aerlingus its hard to know where they'll be in 5 years time although its hard to see 3 carriers staying on Shannon New York given that cities like Birmingham, Belfast and Glasgow don't even have that kind of capacity.
As for the RE/EI deal this winter will tell a lot as Ryanair continue to put 5 738's on ORK DUB even on Saturdays.