I think Deta or someone Delta sized will end up with Hawaiian eventually, but first I think their will be a tie up amongst smaller players. JetBlue/Hawaiian seems like it could be a very good fit.
Many airlines have bought other airlines only to have never benefit from the acquisition because the customer service at many airlines are poor. Hawaiian is one of the best in customer service in which is better than many big carriers with the service skills of a wild hyena with rabies.