eventually the two timelines, the present on island, and the flash-sideways timeline are going to have to connect. juliet said that "it worked." by her saying this it probably created the second timeline. but what if this does not matter because destiny is going to bring them back to the island. i have some reasons that explain this:
1.) john locke in alternate timeline was given jacks business card, and says that there is a chance he could fix him. lets say he does eventually go and see jack(even though the card was ripped and helen doesnt care about his disability)...jack fixes him and he is no longer paralyzed. so what if when we see john in "pilot, part 1" he was not even paralyzed, jack had already fixed him, and he can walk and is fine.
just a theory i was pondering i am open to all responses.