On the island, the Smoke Monster continues to do his damnedest to get off the island. He’s a bad dude, but not necessarily evil. More like a personification of chaos or some shit. He and Jacob, some sort of order entity, have been on this island as a form of penance. Maybe Jacob trapped them there, maybe it was space elves.
Jack and crew chill with the temple folks and learn about how they help the “gods” continue their ever-long duel by resurrecting or killing or enabling possession. This will have something to do with the nature of Jacob and Smokey, like maybe if one is to eternally die, the universe is totally fucked.
At the end of it all, someone, more than likely Jack, Sawyer or Saiyd will be given some ultimate choice to make, vis a vis preservation of this eternal battle and the life of the island. That person will tell them to eff off and this time loop will cease to be. There will be some sort of tender moment as the realization sinks in that they’re done for, but most will accept the end and rejoice in grasping destiny by the balls and telling it to go to hell.
That, or Hurley makes some goofy/impassioned statement and Jacob and Smokey are moved to let things end and be friends. It will be super cheesy but people with say they cried.
As it turns out, the alt 2004 timeline is kind of a “what if” mixed with a “maybe that’s what REALLY happened”. It give them opportunity to tell happy/better endings for these characters if destiny Jacob and crew hadn’t been such douches. But, if they’d actually done the last 5-8 episodes like that, people would’ve been super pissed off at the ROTK style ending, so they’re having their cake and eating it, too.
Ultimately, it be like an inverse of the BSG ending. Not so much that God did it, but gods coulda done it, and the awesomeness of the human spirit made them realize they shouldn’t or some horseshit.
This is all bullshit, but I wouldn’t be surprised if elements of it pop up during the season. I have absolutely no faith or trust in the Lost creators. Oh, it’s a show that I like and have really like a lot, but I still think they’re completely winging a bunch of it and the whole thing will be less than the sum of it’s parts. They listen to their damn fans, the shitty ones anyway, too much and for a show like this I think that’s a major mistake. Anyway, I’m on the ride until the end.