This is mostly taken from comments I've posted other blogs but would like others to think about it. Many times now I've posted on blogs arguing that Christian was in fact MIB. My arguments were as follows.
"I think it was MIB, in several circumstances. Really the only times I am certain it wasn't was when he appeared to Jack off island. But I think that was explained simply enough by the fact that real ghost Charlie said a real ghost would come see Jack (Christian). As far as on island, look at the facts.
He appeared directly after the coffin of Christian's landed on island, exactly the same scenario of when MIB took Locke's form.
Some people use the missing body as an argument, however I think everyone agrees MIB appeared as Yemi whose body was also missing. I think MIB simply takes the bodies he replicates so people that look for them will actually believe that's who is walking around. However on Hydra Island, that probably wouldn't have been as easy to reach his stash of bodies. Plus he was on a tight schedule lol.
Everything he said to John furthered MIB's causes.
Claire started acting creepy and infected like after she joined Christian that night in season 4.
He told Sun and Frank to wait for Locke to come and lead them, and this was just after they heard the Monster in the jungle.
Christian has not appeared a single time chronologically after Flocke appeared.
Lastly, MIB SAID that he couldn't cross the water, but we also know he lies. How did he get to Hydra Island the night after 316 crashed in the first place then? Or how about when he came back from Hydra this season without Sayid? Unless Sayid and Desmond both swam the two miles back across (which I doubt) Mocke didn't take the boat back. I think he can cross water considering he can vanish in an instant and suddenly be somewhere else (as in LA X Part 1, in the foot). I simply think he can't leave the proximity of the island. At that time, the freighter was in the proximity considering Jin started jumping through time. So yes I think MIB was the one who said that to Michael."
Tonight after the revelation, I initially thought, "Yes, now everyone will finally accept that what I've been saying all along is true." But a few seconds later I started thinking and I realized most people who didn't believe it before will still not believe it now. Even when it was blatantly obvious last season, before it had to be said out loud, they refused to believe it. Now that Darlton decided to clarify they still doubt! Another example is that it was also blatantly obvious at the end of last season that MIB was the smoke monster, yet at the beginning of this season Darlton expressed how surprised they were that people needed further clarification of that. Sorry for my rambling, but my point is this:
Many people complain about how they're answering the questions in such a casual "someone states it" type way. Yet if they don't have someone in the show do that, no one accepts it as fact. So many people need to be blatantly told, and just as many refuse that answer even then.