Y'know, they never did bother to explain Walt's powers yet, or why pregnant women can't have babies on the island after the incident, or the magical box, or dead people visiting hurley, or the giant hurley bird, or the psychic getting all freaked out about aaron and then later the psychic claiming he was a big fat liar. It would be hilarious if the last episode just has an hour long monolouge trying to plug up all the unnecessary plot devices they have created.
I really miss season one.
edit: I think Walt pisses me off the most. Especially since they like to have him cameo at least once a season with no further explanation to what the fuck was his deal in the first place.