From an interview done with show runners Damon Lindelof and Carlton Cuse by Doc Jensen over at EW.com, here are the key points of whats to come during the remainder of LOST:
-Episode 5 deals with elements of time travel.
-In episode 5, Lapidus will explain why the satellite phone can't contact in the outside world.
-By the end of the season, we'll know who was in the coffin as well as what's happened to Jack to make him want to go back.
-No answers coming on Jacob and the cabin this season, although we may see it again.
-More details on The Purge, Adam & Eve and another station are coming, but not this season.
-Ben's List for Sayid is linked to who place the wreckage of Flight 815.
Source & Rest of Interview: EW
Summary by DarkUFO