The Body-Swap Theory by La

When I first saw the ALT (I know TPTB don't call it that, but I will for brevity's sake and for lack of a better term), I thought "Man, I really hope they aren't going to erase everyone's past... all that we've watched and come to love about the characters so far." But then I had a thought.

Perhaps, just perhaps, the two timelines will converge in the sense that the ALT is the "escape." Before, if anyone tried to leave the island, they had to get back to their crummy lives (cf. Smokie's "Locke knew how pathetic his life in the real world really was"). Kate was a fugitive, Sayid a killer, Hurley still unlucky, etc. But now some of that has changed.

Granted, Kate is still a fugitive, but perhaps she will be exonerated. Perhaps Sawyer will still be redeemed in the ALT. Perhaps Jack really will fix Locke. Everything changes. For the better.

What will happen, then, at the end of LOST is that everyone will snap through time and space somehow (much like Desmond's back and forth in The Constant) and end up with their off-island ALT bodies, waking up in a new world where they don't have to lie about the island or anything. They still retain their old memories, but everything is better now. They still know each other (they have already begun to meet one another in the ALT) but have all their old memories. Dead characters live again. Charlie will be able to marry Claire, etc. Ergo, happy ending.

Now perhaps there won't be a happy ending for everyone. But generally, I think that the ultimate escape from the island is not "leaving the island" per se and returning to the outside world by physical means, but "leaving the island" by time jump into their new ALT bodies.

The result? Both the past seasons and the ALT are meaningful.