I agree that Kate wouldn't steal Aaron. People make her out to be this horrible person, but she's not bad at all. Fair enough she killed her stepfather, but she thought she was protecting her mother. If anything, she's just slightly deluded. And the idea that she would have taken Aaron in hopes that the court would be lenient on her is ridiculous, as Kate was adamant to keep Aaron out of the court anyway.
Something definately happened to Claire to force her to give Aaron to Kate, whether she is killed or perhaps kidnapped or something. I doubt Jack/Kate/Hurley/Sun/Sayid would willingly split Claire and Aaron up like that. I think Hurley at least would have given up his seat to Claire, so something definately happened to her. Actually... I hope she's not dead...
