Just a wild guess but I think Sawyer will be the "new" MIB (the substitute) and Jack will be the new Jacob. Somehow I think MIB is going to con Sawyer to be "stuck" on the island (sawyer is emotionally vulnerable at this point). Both Jack and Sawyer have clashed throughout all 6 seasons with some tensioned filled scenes but yet both are still alive despite these clashes. Maybe by the forces of the island they instinctively feel that they cannot kill each other. MIB did mention he was “once in love”, which may have been taken away from him by Jacob. Maybe Kate is to Sawyer and Jack as to MIB’s love was him and Jacob. Locke is out of the question bc dead is dead. Especially now that the show confirmed that MIB is stuck in lockes body, I’m assuming there will not be two lockes roaming the island at the same time. I can just picture the final scene of show with Sawyer and Jack on the beach with a cruise liner approaching the island and Sawyer saying to Jack, “you brought them here”. Just a wild guess, feel free to criticize.