I think that whoever a side from Claire who raises Aaron is the problem.. Charlie plays daddy to Aaron on the island and ultimately dies.. He sacrifices himself to save Claire and Aaron.. For some reason off the island Jack is helping raise Aaron, he ends up a pill popping drunk, trying to commit sucide and all..

I recall that our favorite psysic tells Claire that she has to raise Aaron becuse DANGER SURROUNDS HIM WITH OUT HER GOODNESS IN HIS LIFE... So could it be that anyone who is raising Aaron is in danger.. I don't think it is Aaron who is at risk but anyone trying to care for him other than Claire..

Could this mean Kate could also end up in danger?

__________________
Please don't give up, Des. Because all we really need to survive is one person who truly loves us. And you have her. I will wait for
you. Always. I love you, Pen

DESMOND: I love you, Penny. I've always loved you. I'm so sorry. I love you!
PENNY: I love you too.
DESMOND: I don't know where I am, but--
PENNY: I'll find you, Des--
DESMOND: --I promise--
PENNY: --no matter what--
DESMOND: --I'll come back to you--
PENNY: --I won't give up--
BOTH: I promise. I love you.