If you're hoping for the next (and final) season of Lost will answer all mysteries and explain all questions, you're in luck, says co-creator Damon Lindelof. But certain things will remain afterwards, apparently.
Talking to the Hollywood Reporter about the possibility of a Lost movie to follow the series, Lindelof said,
There can always be a movie. I mean, twenty years from now they could reboot it, or three years from now, they could try and continue the franchise. But for us, again, the show has always been about this group of characters... and at the end of season six, their story, all their character resolutions will happen. You know, just like in NYPD Blue or er, the hospital will continue to receive patients, but the characters that we loved and cared about, and invested in, their story is for all intents and purposes over. So, for us, I think the biggest mistake we can possible make is leaving some mysteries open or dangling story threads so that the audience has to pony up money three years from now to go and see continuing adventures of the island.
I don't know why I'm surprised to see an allusion to the fact that the island will survive the show - It's not like I expected it to be destroyed at any point - but there's something surprising about Lindelof comparing it to er's hospital, don't you think?