Some Lost Conjecture

After watching last night's episode of Lost, I think I have an idea as to why Jack feels such intense, suicidal guilt off the island. It kind of clicked for me when they revealed that Kate's son was in fact Aaron. Claire's son. For some reason, Jack was forced to choose between Kate - who he loved at the time - and his half sister Claire. He chose Kate and now regrets the decision. This is why he doesn't want to see Aaron after Kate wraps up the court room drama. Seeing Aaron reminds him of Claire and maybe something he did that caused her to be left behind or even worse, die. This theory also would require Jack finding out that Claire is his half sister. Maybe a possible showdown with Christian in the future? But wait, I thought Christian was dead? Maybe a showdown with Christian's ghost courtesy of Miles the ghost busting extortionist?

This raises another interesting question. Did Desmond lie to Charlie? I can't remember from the episode whether or not we got a glimpse of Desmond's premonition that Claire and Aaron would leave the island on a helicopter similar to the glimpses we received in the episode where they find Naomi. So I could be completely off base here. However, it seems odd that Desmond is the one boarding the helicopter a couple episodes ago and now it appears that Claire does not make it off the island. Did Desmond cave to his selfish desires to reunite with Penny and sacrifice Charlie? I hope not because I thought that conflict was resolved and I really like Desmond and want him to overcome his weaknesses. However, if Desmond is in fact off the island (I don't think he is one of the Oceanic Six though) this would play right into the theme of all the survivors feeling even more guilt off the island as opposed to the guilt they felt on the island.