So I just watched the season opener. It set up a number of hit you with a sledgehammer arcs:
1) Family. Can't live with them, they can't live without you.
So, Dean's got himself a happy little suburban life, nuclear family. Best friend, wife, son who probably is his genetically. And it's all lovely, except for the whole guilt thing about his brother being in hell and all.
My bet at this point is that Dean Jr is toast as far as the not-becoming-a-hunter business. Not only is it heavily implied there is some kind of genetic component (or supernatural blood bond thingie), there is simply no way sonny-boy is not going to be a huge target. So it's learn the hunting life for him, or else fun with victimhood for him.
And yeah, of course he's Deans son. Who are you kidding.
So basically we are going to have a season arc where Sam and Dean flash back to their childhood while putting Ben through the same hell they went through. All while Grampa looks on with encouragement and concern. Like the manipulative bastard that he is.
Very much a "sins of the father" kind of deal.
Speaking of family Grampa is definitely one to watch for. My gut instinct is that he's this season's big bad. Well, not totally. Actually I think God is the big bad.
2) God.
God's not exactly a loving deity in this universe. He's kinda a douche. And no, I don't think he's Chuck, even though that was implied last season. God is the one thing that could have pulled Sam and Grampa out of their respective places. My feeling? God is bored. He needs a talking to. Maybe even to be killed and replaced with some other deity who doesn't dick around with creation the way he does.
This is because there are other deities wandering about. Obviously this judeo-christian guy isn't the only diety out there. Death is much older. So the question is, is there any way to wrest power from this guy and replace him with someone who is less of an ever loving asshole?
My hope is that Kripke will cameo as God for the final showdown. Because that would be fucking sweet.
3) On a more meta note, the writers love to please their fangirls, but they love even more to dick around with them.
So, Cas is missing for the first episode with no gaurentee he'll return. But he will return as a gift later on. Wincest has been tampered with by having Dean in a canon relationship which he isn't going to abandon for his brother.
I expect Lisa to stay. Until she's developed her own screaming fangirls. Then in a fit of giggles the writers will kill her off. Because they are dicks like that.