I just had a creepy thought about the ending as it relates to children appearing on the Island.
The final scene could be like this:
The 815ers, the ghosts, the zombies and castaways meet in a small clearing in the jungle. It would appear that this would be the final showdown between good and evil and Jacob and Flocke. Two lines meet like old steam locomotives heading in opposite directions on the same track. When they meet, they stop. Then they hear a rustling in the underbrush and whispers that quickly grow louder. All the adults turn to look at the area. Their eyes pop in astonishment.
From out of the jungle comes an equal line of children. Their dirty faces stare ahead at the adults. And the adults have a feared recognition in their expressions, for they are looking at themselves at a young age!
The children in unison say, "You screwed up our lives. And we want them back!"
Cut to LOST logo with the sounds of mechanical Smokey noises and screams.