There's something that has been bothering me... one of those little details that gets so easily overlaid with other distractions.
When Jin confronted Richard on the beach, she showed him the 1977 photo and asked if he was still alive. Richard replied that "they're all dead" and that he'd seen them die.
Now, did he didn't say that he just saw the whole Dharma Initiative team get exterminated; he remembered all of the Oceanic 815 survivors who were present. But... Juliette set off the bomb and they were all transported back to the "present" time. Jin was still alive. Yet Richard saw him die. How can we account for this?
I wonder if it's all due to some kind of paradox to time travel. That perhaps there was a kind of "split off" that took place. In one permutation, the bomb didn't detonate. And later on, the survivors are rounded up with the other Dharma Initiative team and killed (and I wonder if Jack and Kate escaped, to later die in the caves--remember the two bodies there). In the other permutation, the bomb went off but somehow interacted with the anomaly to send the survivors back to the present time--was everybody else who remained behind decimated?
And then of course there's the flash-sideways. Some people have speculated that it is the "next cycle"... the true future.
Anyway, I'm having a hard time getting a handle on it all... I'm hoping future episodes will begin to piece it together. I certainly hope that we get some solid answers with just a little reasonable ambiguity left behind for interesting discussion. Part of me does wonder if this series is meant to educate the masses in some way. I mean, look at the long book reading list that came from all of it. And the degree of complicated meanings delving into various incarnations of folklore and mythology. I hope they eventually open up the "Lost University" archives that have been kept exclusive to the Season 5 Blu-ray owners.