I think the ultimate game-changer in the war between Jacob and MIB will end up being Desmond, if and when he returns to the Island. Faraday has stated many times that the "rules" don't apply to Desmond. On the surface, Faraday was talking about the rules of time travel (Desmond has the ability to change the future, Desmond was able to see the white light during the time flashes). But is it a possibility that Desmond is so special that the apparent rules governing the Island (the rules that Ben and Widmore, and Jacob and MIB, appear to play by) also don't apply to Desmond? These rules seem to focus around who you can and can't kill in conflict, but I feel like if Desmond comes back, he will transcend these rules. What do you think?