With out the help of Alaska's west coast routes I don't see JetBlue and Hawaiian airlines serving any great feed . Jetblue doesn't fly to enough cities on the West coast to really connect enough passengers. Thy already fly to JFK so we connect them from there . And they fly to LAX.
Now some investor put up a map of Jetblue , Hawaiian and Alaska's routes combined . That would be a real threat and route map compared to others. Jetblue and Hawaiian solo , Meh, doesn't work well , unless it's part of a long term 3 way merger to go down in the future.