In their eagerness to provide cliffhangers that will bring viewers back next season the producers/writers of Lost put together a cheap, exploitive episode. Anyone watching the show with an interest in character development will need to wait until next season to see if anyone at all is rewarded for coming to terms with his/her past. To date, the only two who have gotten of the Island after an unselfish act have done so by dying.
There was one scene (from minutes 53-55), that includes a hint that may - or may not confirm my previous suggestion that the Island represents a last chance for each character to make amends for harms done in the past. In this scene Sun asks Shannon if she thinks that they are on the island because they are being punished for past secrets and lies. Shannon asks who would punish them. Sun answers: "fate". Claire walks up and says no, it isn't fate.
Clearly. the script writers have inserted some Ghosts - religious concepts hidden behind the pixels - to keep us guessing. We could spend the whole summer debating the choice of names and their philosophical implications (for example, Locke). This debate assumes that the writers have a consistent concept behind the script and that ABC hasn't distorted the concept in order to attract audiences.
My own guess that their is a consistent concept - keep throwing out obscure hints in order to bring viewers back every week. I had thought about watching the entire series again and teasing out the life task that each character was sent to the island to perform. After last night, I'm not sure it is worth the effort. Comments, anyone?