One thing that came up to my mind when i saw this finally is the fact that you can see people like the Hurley playing chess ecko, talking to charlie. Jack talking to is dad, etc. So Locke saw Claire in Jacobs cabin and when Kate saw her in her dreams. Would that mean she i dead? if you think about it, she was in the house that exploded when locke's camp got attacked, and she only had a few scars when sawyer got her..