Alot to think about here. I agree with pretty much everyone that Dean has changed (and so has Sam). He's much much darker, and more cynical, with that edge of bitterness. I don't know how a human could not be, after everything he's lived through, so it strikes me as realistic even if it isn't pleasant to watch. But I don't think Dean is as incapable of empathy as some others do. He's damaged enough to be egocentric, but not so damaged that he's without caring for others. Especially Sam, but others in a general sense too. I don't think that's gone - I just think it's been knocked down and dragged around until Dean himself can barely find it anymore. But it's there. And I think it will be back.

That's not to say that I think Dean will ever go back to being the kind of hero he was in S1 or S2. He'll always be darker, and he's capable of cruelty now, much more than he was in those early seasons. So is Sam. But I don't mind a flawed hero, especially when it seems like the inevitable place the story would go. The 'saving people' - I don't think it's gone.