Merry Lostmas!

For all the other plots, themes, and storylines, the core drama in Lost has been between Jack and Locke, or, more abstractly, between "Science" and "Faith". I suspect this dualism will drive the thematic focus of Season 6 as we resolve our character arcs. Jack has seemingly switched over to being a man of faith - his fanaticism regarding Jughead is proof of this - whereas Locke. Well, Locke's dead, mister. What is walking around as Locke is presumably the MiB.

So, it appears we've been prepared for a role reversal, with Jack taking on the more messianic aspects that Locke once embodied. I also assume all of our characters in the 1970's will return to the present day (Jacob said as much with his dying words: "They're coming.") for a final conflict.

Also recall from very early on in the show (Locke's speech to Walt about Backgammon in season one), the show has set up binary conflicts between Light and Dark, Logic and Faith, Good and Evil, but presenting all these binary conflicts in degrees of gray.

Resolution of any of these "conflicts" is improbable, as there is no resolution possible since there's not really a conflict. Regardless, this whole tale may play out as the motions of bored God like beings, trying to prove a point regarding humanity's higher nature with humanity's lower nature.

Only one way we find out: We start tonight!