I do not have much to say about Supernatural's ninth (!) season opener. I feel like this is the tenth time we've had a life-or-death battle inside Sam's brain, and at least this time there weren't two Sams fighting each other. And basically, at this point, everything bad that happens is either Castiel's fault or Dean's.
In a nutshell, even though Dean stopped the "closing the gates of Hell" ritual because Sammy was going to die, Sammy is dying anyway. Which doesn't seem all that surprising, and really makes you wish they'd actually closed the gates of Hell while they had the chance. So Dean puts out a general distress call to every one of the angels who fell from Heaven, hoping one of them can help. Some evil angels show up, but so does the apparently nice Ezekiel (Tahmoh Penikett) who possesses Sam, allowing him to heal Sam's body, and perpetrate whatever incredibly evil acts Ezekiel wants to perpetrate.
And along the way, inside Sam's head, Dean and Bobby play out a version of this scenario:
(With Bobby playing Anthony Ainley, because beard.)
And meanwhile, Castiel hasn't quite figured out that being fully human means he needs to eat and drink water and go to the toilet, and this comes as a recurring shock to him. He meets a nice angel, who created the Grand Canyon and wants to go see it, but she turns out to have designs on Castiel's vessel. He crashes her car and she's injured enough for him to stab him — but not before she warns that all the other angels are going to want to punish Castiel for his role in booting them all out of Heaven.
So basically, Dean is going to be confronting the results of his failure to close the gates of Hell, while everybody is going to be faced with the fallout from Castiel getting tricked into helping with the expulsion of all the angels from Heaven. If this show runs on angst (and it does) then it's going into season nine with a full tank of gas.
But we're still more excited about what (or rather who) is in the trunk.