If their intention is for us to see Sam as a selfish, callous brat then they're doing a great job but I can't imagine that's what they want.

No, I'm sure it's not. ::sigh:: I mean, I don't know what to say. I feel personally as if I'm inextricably caught between canon and fanon, between first season and fourth. Sam HAS changed, radically, and maybe there's some validity to the remarks that some people have a tougher time adjusting to those changes than others. I don't want Sam to be a fly in amber. But I do want to see him -- incorporate things, learn, and such instances as the insistence on Dean telling him about Hell suggest that for all he has encountered, gone through, and god knows that's a pile -- he hasn't really changed his perception that the world honestly DOES revolve around him.

I dunno, I wish I could be more reassuring. :-/