Aaron, The Infection, and Free Will vs. Non-Free Will by Goombajuice

My theory has a few parts.

Part 1. (the infection)
We know that the creators said that there will be a "war" of some sort in season 6. I think it's clear they are setting up the infected vs. non-infected (or claimed by the smoke monster and not claimed by SM). I think it's also clear the the smoke monster can only claim bodies on the island that are dead (so far, as I see it, the team consists of Claire, Sayid, Christian, and Locke).

Part 2. (free will vs. non-free will)
Now I used "non-free will" instead of "fate" because fate has good connotations, but I think the MIB/Smoke Monster has more sinister intentions. So Jacob = free will and MIB/Smoke Monster = non-free will. The reason I think that (besides the obvious from their conversation when we first met them) is that Jacob can't directly manipulate and basically "cheat" like the Smoke Monster can. Jacob can only simply touch you or give you a little "push" and the rest is up to you. The Smoke Monster deceives and does things that would normally be impossible to get the losties to do what he wants (take the form of other people, physically do harm, etc.)

Part 3. (Aaron = Claimed)
This was something that was speculated by many people for a while, but I think was given a little more credence with the last episode ("What Kate Does"). When the flight 815 originally crashed on the island Claire stated that she "hasn't felt the baby since the crash". And eventually she starts to feel the baby and she has the child a few days (weeks?) after the crash. Yet in "What Kate Does", Claire goes into labor almost immediately after the flight lands. And it also makes sense why Ethan would be giving her vaccinations, to try and ward off the infection. I think that Aaron died and was later claimed. And this could be what the MIB/Smoke Monster means by "I want to go home"...Aaron wasn't supposed to leave the island, the island is home of the Smoke Monster. Maybe it's a stretch, but I think it's in the right direction.