My biggest maybe-spoiler relates to what the "unLosted" characters in Timeline-B are going to do for their part of the resolution. Given all the stuff about time-travel and teleportation I can't help a tendency to imagine a STAR TREK-y scenario in which all the "unLosteds" get together and their bodies give off an ILM light-show as they magically transpose the two continua. I know intellectually that's NOT going to happen, but I have to say it to get it out of the way.
A friend and I recently brainstormed a more likely scenario based on what the type of narrative stratagems that the LOSTguys have already used before.
Start with the notion of "eternal recurrence," as expressed in Nietzche's THUS SPOKE ZARATHUSTRA:
'Everything straight lies,' murmured the dwarf disdainfully. 'All truth is crooked, time itself is a circle.'
Now, in place of Nietzsche's "eternal recurrence," LOST gives us what I'll term "eternal recursiveness," in which patterns continue to propagate themselves in different arrangements. LOST's attitude toward the repetition should probably be distinguished from Nietzsche's concept, since for Nietzsche the only expression of "free will" in this situation was "amor fati," the love of one's fate. I think that the LOSTguys might be moving toward some less Classical, perhaps more Postmodernist conception of fate, but in any event, "eternal recursiveness" isn't quite the same as "eternal recurrence."
Now, how did the Oceanic Six work to alleviate the problems of the Island (even if they alone didn't effect the cure as such). By going back to the Island.
So how will the "unLosteds" right whatever's awry in two universes? I'm guessing that they, too, will have to get on a plane again, and fly to where an island hasn't "disappeared," but where one supposedly has never existed.
Where it goes from there, who knows. But that's the sort of established narrative motif I could easily see the LOSTguys repeating.
Jack and Claire are apparently going to the airport to claim their father's body. Since Desmond is the source of the message the coffin may or may not actually be there. If it is, I don't see that this stratagem leads much of anywhere, unless the siblings discover a clue to the mystery of the music box in the coffin. I'd speculate that both of them will be shanghaied at the airport by Desmond but it would seem to be more important that they should be at the concert the same night Desmond calls Jack about the body. If Jack finally gets to see his dead father laid to rest, though, that may provide some sort of important closure for the series.
Also, Desmond is apparently going to the concert with Kate. Kate will almost certainly have an "ah-ha" moment with Claire once more. Maybe she will repeat her delivery of Claire's baby? Good: I definitely did not want to see Ethan putting his hands down there.
Hurley is off with Sayyid again, doing their ADIOS AMIGO thing. I'm laying heavy odds that they're going to coerce Jun and Sin into leaving the hospital (probably ABANDONING THEIR POOR KID AGAIN), which might be somewhat feasible with Sayyid along for the ride, in that Jin knows he owes his life to Sayyid.
It's vague as to where the concert is, but possibly it's at Pierre Chang's museum, though that sounds like an odd setting for a concert. That would make it possible for Sawyer, Miles, Chang, Charlotte, Kate and Desmond to be there at the same time, as well as Jack and Claire if they indeed don't get hung up at the airport. Charlie might even find some excuse to show up, and my friend suggested that Jack might invite John Locke to the show, though the act sounds a little out of character for Jack. Odds are also fair that David's mom will be there, and that it will be Juliet, who will in turn meet Sawyer for that coffee she suggested back in Timeline-A.
That leaves Ben, Daniel, and the Widmores with no particular reason to be at the concert, but I'm sure they'll get in somehow.
As for Timeline-A-- well, maybe I need another post for that after all.