I don't think that Jacob is the smoke monster. My stoner senses tell me that Jacob is more along the lines of Desmond, someone who got caught in some island anamoly and as a result is now kind of invisible (there was a second or two where you could see him, it was just pretty dark). As for the tk, meh.
Although Ben is a stone cold liar, I do believe him when he says he can see Jacob. Of course, the episode would lead us to believe he can't hear him, however...