What an episode! Made me have a few revelations. LOST is turning into a giant Sudoku puzzle for me. Once one piece of the puzzle is revealed, the others finally start to fall into place.
1. Is it possible that Ajira 316 crashed in the same manner that Oceanic 815 crashed? If you remember in the first few episodes, the survivors' recount the crash, how they all just blacked out before they landed anywhere. We didn't really catch a glimpse of what the crash may have looked like until this episode. That weird "time crunch" thing whisked them off to the 1970s when the Dharma Initiative is presumably in full force on the island. Again, we find Jack on the jungle floor, Hurley in the water, Kate on a rock in the water. Again, they find themselves unscathed, unhurt, and wondering what the hell just happened.
Maybe after 815 crashed, the same thing happened, where the survivors never physically fell out of the plane, but were popped out of existence for a temporary time period until they popped back into existence, scattered about the crash area. If you don't believe me, think about how Bernard was found in the trees, still buckled into his chair after the 815 crash. If he fell from the sky, the chair would have just plowed through the canopy, breaking limbs, and crashing to the forest floor. He wouldn't be stuck in a bunch of branches. Thus, he probably popped back into existence there.
2. It appears that the Oceanic 6 weren't the only things that needed to be on that plane. There were multiple other, ahem, similarities between the passengers found on 815 and 316. Sayid was taken into custody and was being escorted onto the flight, much like Kate, by an air marshall... who suspiciously looked a lot like Ana Lucia.
Hell, even Frank Lapidus was flying this plane. If you think back to last season, during the episode where they're showing the back story of the freighter crew. Lapidus sees the news coverage of the fake 815 they found at the bottom of the ocean, and calls the hotline, eventually revealing that HE was supposed to fly the plane that day! Now that he's on the plane, like he was supposed to be, his fate has been corrected.
3. Taking the Lapidus thing even further, ever wonder why the original pilot was killed by the smoke monster in the first episode of season 1? Very curious that the monster either retrieves people and pulls them back to the temple, or discards those that aren't "supposed to be there". The smoke monster investigates the fuselage in season 1... finds out that the pilot wasn't originally supposed to be on the flight, and kills him.
4. Another season 1 connection for ya, Richard Malkin, the psychic from Claires flashback, insists that Claire be the only one to raise her unborn child... and suddenly has a change of heart and insists that Claire gives her baby to a couple in Los Angeles who will take care of it. He goes on to INSIST that she takes a flight that leaves in the morning, no other flight, it had to be 815.
What did he know? Is he in cahoots with the Others, who in turn, has a contact in Mrs. Hawking in LA, who appears to know what flights come dangerously close to the island? One has to wonder...