I still don't buy it. It's like watching a movie at about the half-way point and they get you thinking one thing only to throw you a curveball at the end. I think the MIB was a man and sort of fell for a trick by evil that was on the island. The evil took MIB's body (Jacob's body) and they are now in each other's bodies. With the new body the evil is allowed to go off island and tempt those to follow him, leaving the man who was once Jacob trapped. Maybe he knows how to reverse the process somehow and minds will swap once again allowing C. Widmore to destroy the true evil. With the evil destroyed there is no longer a need for an island so thus we see it submerged under the ocean in the part 1 of LA X. Everyone who was ever tested by the islands evil will be placed back in their appropriate times and hopefully a shot at redemption as we are seeing in the FS. Hopefully this will be the timeline as a result of evil being destroyed at least for a while. I having a sneaking suspicion that they will pan back to the island after everything has played out and you will see the evil start to resurface starting the whole game over again.
I believe that a key point to tonight episode goes back to what Flocke said last week. I gave her (Claire) something to hate. I believe that the smoke monster was being controlled by the evil trapped in Jacobs’s body all along up until the time that Jacob was killed. When Richard saw the smoke monster kill Isabella and combine that with what Jacob told him he was given something to hate. I believe that Jacob is manifesting all the ghosts on the island as a way to control people or push them towards his agenda. He used Hurley to talk to Isabella to convince Richard to stay loyal to his cause. I don't believe that the writers will end up just making the island hell. So with that said why all the ghosts of dead people if not a form of control used by evil to manipulate those who haven't seen evil for what it really is. Put yourself in the MIB shoes. If you came to the island as a man and were tricked out of your body wouldn't you want to get the hell off the island also? Let's just say that someone put a guardian on the island to keep evil in. Why would you make that guardian human with the ability to be killed and eventually let the evil out anyway? Now if the island is what is keeping the evil in and evil found a loophole in the form of a human(s) to trick in order to spread his malevolence through them. Maybe there is something about Jacob's body that allows the evil exist in it and now it is coming to its useful end and now the evil needs a replacement body in which to continue its existence.
It just seems to me that this show has been keeping us guessing for going on 6 years and now everyone wants to definitively say that Jacob is good just because he says so. Does he have an honest face? Is it because he is dressed in white? Looks can be deceiving and a criminal with a dishonest face would have to find a change of career quickly.