The producers have claimed that MIB's real name will be important to us when they reveal it and as we have seen so far this season ( and "The Incident") they have gone to great lengths in the show to protect his identity. He is always referred to as him, the black smoke, Locke and now in "Ab Aeterno" as The Man In Black. In the last scene of "Ab Aeterno" with Jacob giving MIB the bottle of wine i was hoping Jacob was finally going to say his name but it wasn't to be. I think his name will be one of two options, either 1.A character on the show we have already seen and know of so when they finally give the big reveal our jaws will drop like they did when Locke took Ben into the statue and we realised the whole of Season 5 it wasn't really Locke but MIB or 2. His name will be some well known deity/ mythological entity such as Lucifer, Death etc.. I cant see how it could possibly be anything else but one of these options. I think as much as LOST has been the ultimate mindf*&k show of all time we still have yet to see the ultimate mindf*&k moment. Any thoughts/theories as to who the heck MIB really is??