I've been saying since the episode of Eggtown that Claire had to die, one prevalent theory now is that she already has.
Two episodes ago, Claire's bungalow was blown to smithereens by the mercenaries. Some argue (and the argument is a good one) that she actually died in that explosion, and the "Claire" that Sawyer rescued from the wreckage was actually her ghost (much like the ghost that Dr. Jack has seen of his father, or that Hurley has seen of Charlie in his flash forward).
It would explain the fascination that Miles seemed to have last week regarding Claire, as he is clearly drawn to the dead, but this vision of a substantial ghost able to walk, talk, and hold a live baby, is different then any ghost he's seen or communicated with before causing him to be unsure of exactly what is going on, but knowing that something is, so he keeps a close eye on her trying to figure it out, causing Sawyer to institute his 25 ft rule.
At one point, Miles tries to touch Claire, offering to help her navigate a trail, but is stopped by Sawyer, I think it is because there is something about her that has drawn the interest of his "ghost-sense" and he felt he might be able to understand it more clearly if he touched her.
We now know that the ghosts can hold babies, as we saw Dr. Daddy holding his grandson before he took Claire with him. If she's dead but doesn't know it, that could be what Dr. Daddy has come to explain to her.
The other possibility is that she isn't dead, and in fact won't die at all. The reason that she isn't with Aaron as one of the Oceanic 6 is that she is still missing when the "rescue" happens. This could also explain why
Sawyer isn't off the Island, because he refuses to go without her.
Miles could still be interested in her, because he sees something about her that has drawn Dr. Daddy to take her away, some affiliation she now has with the Island due to her near death experience in the bungalow.
My feeling is that one of these will be true, meaning that either Claire isn't going to die or that she already did.
Until Next Time, hopefully we'll finally find out a little more about Jacob tonight, and I wonder if Locke's flashes will be your typical flashback or if we might get the first ever flash forward not involving the Oceanic 6.