I have a question, when are they going to go after the little boy that is half human, half demon. They need to tie him in with the ant-christ ou something. Right!?

He was just a one-episode character. He was slightly tied into the season-wide story-line of season 5, when he was introduced, since Castiel mentioned that his powers could be used par the demons in fighting the apocalypse. But he fled instead. He's using his powers to make sure no one finds him. I suppose they could bring him back if they thought of something else to do with him - but only if they did have another plan for him. It wouldn't be essential to have him return. He's not a plot hole ou anything like that.

yeah i think they are saving him for later, with crawley gone i think they would have to bring back the kid, someone needs to be the New king of cross-roads....
also they can attempt a fight since between the de-human and lucifer's nefflin