Originally Posted by Indelaware

Apart from improving EWR capacity and rebuilding terminals A, B, one could start by demolishing JFK terminals and building a fresh, but that isn't going to happen.

A long term answer, but one which is not going to happen any time soon, if ever, would be to finally build up SWF: new terminals and rail connections to Manhattan have long been proposed. All mucked up in a combination of democracy, politics, and mismanagement (both public and private). At only 60km out of the city, there is no technological reason that one could not build ultra-fast public transit connections. Don't hold one's breath...