I was thinking that in 2007 the Losties vanished from flight 316, right? As far as the other 316ers are concerned, there is no explanation for those folks disappearing (despite what we know, which is they went back in time). There has to be an explanation that makes sense to the people on that plane (316) and to those they left behind in LA who are gonna be asking questions!
I'm wondering... what if the Sideways Losties all somehow hop on flight 316 X in 2007, which will crash on Hydra again. The Sideways-ers will disappear off the plane because they never really existed to begin with. This time, they really disappear instead of going back in time. Our regular Losties (who are at the temple/lighthouse/cave/jungle, etc.) will connect up with flight 316 X and will be able to say they were on that flight and get rescued and go back to where they're supposed to be. Or something like that. Does it make sense?
I don't know. I'm so confused! It's all so convoluted - but I LOVE IT!