Jack was on the booze and crazy pills by that point
I think there were some details in there he can't know. Like white shoes.
I really liked the most recent episode.
Spoiler The woman who is guarding all of the candidates said that the black smoke can take the form of other people, but since he's in Locke he can't change shape anymore- Any thoughts as to why?
I would say that it was the man in black who appeared to all those people as images or dead people, but when Richard's wife appears it seems that she was somehow separate from the smoke/MIB.
But when Ben went down to that room (was it under the temple), and the black smoke appeared, it showed him images of his past, then his daughter showed up and was like, "follow Locke". The black smoke could have been the Man in Black, but he took the form of Ben's daughter- but he shouldn't have been able to do that if he could only be Locke.... unless he was only trapped in Locke's form after Jacob died.
Also, I recall that Ben had a way of summoning the Black Smoke.... Anyone remember the mechanism he used to do that?
Things do seem to be pretty straight forward, but then there are all these details.... I can't tell if they are just sloppy last minute rewrites, or if they are part of a masterfully interwoven story designed to throw you off at the end

Spoiler The only person who could see Richard's wife was Hurley, as he can see dead people.
Ben went down under his house and did something with the water to summon Smokey. http://www.youtube.com/watch?v=nyX6_j2otns
In the same episode a dead woman appears, totally convincing, with whole memory, image, feel. And viewers think she is black smoke in first and then a real ghost in second. I mean isn't that obvious it is the same thing? What's the difference?
At this point I only buy something like Black Smoke can disguise every dead person but Jacob. But even that doesn't work for me.
Christian seems to be on Jacob's side somehow. I seem to remember seeing him in that cabin that Jacob was said to inhabit a few seasons back.
I believe that was MIB too, and Christian was her "friend." like MIB Locke. But the real question in my mind is what if there is a third person. The "help me!" guy in the cabin.
I'm most certain that Jacob or MIB(or both)is actually someone in the show. But thousands of years later after lot's of time traveling(so before). But can't figure who is who.(actually I think MIB is Locke himself(or Kate!). His mother was crazy, playing games on people(Boone incident). Jacob could be Hurley or Jin. But not sure on that. Jacob could be a women too, why not Kate.(I love Kate

). Final, Jacob is... Ben.)
MIB can impersonate anyone but his original character is a [censored].

Spoiler
My fear is at the end Jacob will win and resurrect everyone. So we won't blame him for all the deaths he caused.(Yeah, I blame him for everything.)