Ever notice everyone dies for a reason? (spoilers up to ''?'')

[Teelie]

I think that those who weren't in some way connected to the "master plan" of the island were killed off in the intial crash. Everyone so far who has died since played some role in getting people either going or thinking a certain way. The airplane pilot's death was meant to introduce the monster, the US Marshal was there to set up Kate, Art got them to the dynamite safely (at his own foolish expense) and told them how to handle it, so they could open the hatch. Everyone so far has done their part and then died for a reason, even if it isn't obvious. Shannon's death I'm a little murky on but I think she died to get Sayid into a certain mindframe. He's obviously different than before and seems more willing to torture people in order to get information.

Season 2 spoilers from here on up to episode 2.21 "?":





Ana got Eko, Libby, Sawyer, Michael, etc. to the other camp safely. Afterwards, she was killed off, causing another plot involving Michael and the "Others." Boone obviously got Locke going in a certain direction and set up finding the second hatch.

So far Libby is the only one I can't think of what her role was before dying, besides something to do with Hurley's future and perhaps Michael's. Everyone else is alive to complete their part of this plan, whatever it is.

Whether all of this is apart of the Dharma project/Island's intention or just the writer's using the deaths as a means to an ends remains to be seen.