I'm unsure because I don't knwo why Jack has a problem with Kate's son. It makes sense that maybe it is a child concieved from her relationship with Sawyer. But I think it is unlikely to name her son Aaron, after Claire's son. Anyway, It's a tough call, but I can't wait to find out the answer!

I almost 100% sure, he looks just like him and is about the age he should be whenever they got off the island. Jack probably doesnt want to see Aaron because of something that might have happened to Claire on the island. Man Lost always leaves so many questions in your head...

you probably should make this a spoiler question...

I have a feeling that it is claire's baby although i hope it isnt for the following reasons... If it is claire's baby then that would lead to suggest something has happened to Claire, which i severly hope isnt the case, cos i love claire. I think its nice thing to have a kid of her own, maybe its sawyers and she was lying about not being pregnant to gauge his reaction to the news... seeing he was happy that she "wasnt" pregnant kate figured that she'd leave the island and face whatever awaited her and keep her child off island.
Jack would feel uneasy around the baby for a couple reasons too...
1. its sawyers baby and he still loves kate
2. something happened to claire and he couldnt "fix" her. im sure if he knew claire was his half sister he would want to be around the baby...

i'm been confirmed mate

^^yeh i think he's knows Claire is his half sister and thats why he can't see the baby! D= I hope Claire is okay - i love that girl!