I believe that Jacob is Aaron OR Charlie (Desmond's son) by JFar

This is purley a "hunch" -- I base it on his looks. Blond hair, his coloring, and the fact that he was born on the island.
Being born on this island has special significance, and I believe that issue will be played out in someway in S6.

Also I believe the scene where Claire and Christian are in the cabin with Locke, Claire appears to be as cool as ever. Not like she just was seperated from her son. She knows something about her "son" by this scene. Aaron is very very very important to the storyline of Lost.

I too believe that Abbadon is "older Walt."

A question I put out to the Lost Community is. Who else is both younger and older in these episodes? Walt / Abbadon, Aaron / Jacob, Ji Yeon / Miles Mother. Jack is the key, because "he walks among us, but he is NOT one of us. He's new to the scene I believe.

The big question is going to be, "how do you break the time-loop" that I believe we are witnessing.

These people (all the characters) have been doing this for generations, looping again and again.