I should state up front that I liked this episode. I think they should have made it a two hour lead in so they could have nuanced it a bit, but overall, I was pleased (and possible not for the reasons you would think.) But seriously, after 8 seasons, I would think the CW could pitch for a 2 hour opener. But they didn't, so onward with what we got and why I liked it so much.
So, for 8 seasons, we've known that Dean has a poker face, but we've almost always known what was going on in his head because the show has shown us -- in dialogue, in his decision-making process, in his declarations, in his grief and anger and joy -- from selling his soul to his near year with Lisa and Ben, we've known when Dean was happy, angry, sad, confused and we've known why -- we've been privvy to how Dean thinks and how he arrives at his decisions in some of the best Show Don't Tell writing in Television (And not a little reliance on Jensen Ackles's extremely expressive acting.) Sam has been the one largely clueless about what's going on in Dean's inner and outer life, while the audience has been pretty clear all along what drove Dean.
Sam, on the other hand, shows a lot on his face, but it's rare we've ever gotten to see the thought processes that go on inside that big brain, unless he has some kind of confrontation with Dean -- we may think we know why he's done what he's done, be it taking the demon blood from Ruby while Dean was in Hell, or choosing not to look for Dean in his year in Purgatory. We know what he says, and even, maybe, what excuses he offers, but we really don't get a close-up look at the way Sam thinksor processes those choices when forced to make those decisions. Dean can tease Sam all about being emo, a girl, a bleeding heart, a soft touch, and the truth is Sam may be all those things, but the viewers rarely get to see how that translates from emotion to action (or lack of it.)
So Dean comes across as open, compassionate, thoughtful, trustworthy, and Sam seems to be pegged as being closed, distant, and selfish. Even when Dean acts in selfish ways, there's compassion on the viewer's side because we get why he does what he does, and right or wrong, we're far more willing to forgive Dean his failings because we have empathy for him, than we are with Sam, because what we get with Sam, is the results of his actions, not the process that got him there.
We saw a shift in that at the very end of Season 8 -- both in Sam taking on the trials when Dean missed his chance to finish the first one and at the end when Sam was completely ready (and I'd say, expecting,) to die to complete this one thing and save the world, but even more to the point, hopefully to redeem himself in Dean's eyes.
This time though...this time we finally get to see Sam actually processing the choice he makes. We see the arguments, pro and con; we see them manifest themselves via the two people most important to him in the world, whose opinions, how little or much he agrees or disagrees with them, matter most to him in the world. He's arguing with himself ultimately, and even his discussion with Death (which may or may not have taken place entirely in Sam's head, and therefore the promises Death made may or may not actually hold water) is playing out in Sam's sub-conscious mind, in the subliminal ether of his id. How painful is it to watch Sam find approval only in Death's eyes? To be that much in need of some kind of acknowledgement for what he's both sacrificed and suffered?
He's done, he's ready to go, or to let go, as the case may be, and while I'm the last one to want Sam to exit from this show/universe, for the first time we can see the why of it, the arguments he has, the insecurity about his ability to do more or even contribute anything of worth. Something we've seen Dean struggle with far more visibly over the past eight years.
And he made his choice. He heard the arguments from both sides and made his choice, putting conditions on it he can in no way enforce, but are apparently the only way he can reconcile his desire to stop fighting -- no comebacks, no fall out on anyone else.
And then Dean is there again, with a last ditch pitch; a last plea, presenting himself as the last argument Sam can't overcome. I don't think it actually matters that Sam didn't know what exactly he was saying yes to. There will be fall out, guilt, remorse, secrets -- again on Dean and we'll watch them tear Dean apart over the next few episodes or even the whole season, but Sam said yes to Dean and I think ultimately Sam is going to acknowledge that.
This is, even amid all the brotherly love and bickering, where the crux of much of the show rests, I think. Saving Sam is and always been Dean's job one. It's as much a part of his identity as anything else. Fucked up as it is, it's always been the test of both Dean's loyalty and love, and Sam's too. "There is no me without you," is what Dean tells him via Ezekial's string and can touch.
Of all the people Sam feared his death might harm, Dean was at the top of the list even if he didn't say it - and from the inner dialogue of Sam's dying, he doesn't know that the last time he sees Dean isn't also in his head. From Sam's POV, his own psyche summoned Dean to him one last time to make that argument and Sam says yes.
I think some part of Sam thinks Dean would be better off without him -- he certainly thought so when he said yes to Lucifer and threw himself into the pit. He certainly didn't think his life was worth the time Dean spent in hell.
I do think the fall-out will be huge, but as many things with SPN, much of the conflict is going to be about the whys of how things happen, rather than the what. Sam has been possessed by a demon, been possessed by Lucifer, and been resurrected as a soulless shell of himself. Now he's vessel to an Angel he doesn't know, because Dean asked him to fight, to save Dean. Dean has made a choice for Sam that he can't attribute solely to "saving Sam". This time it is as much about saving himself from a life that has less and less easily discernible purpose or point.
So, did I like this episode -- yes, but not because of what it sets up, but rather because for the first time in a long time... it showed us a Sam who does not appear selfish, or driven by guilt, but a Sam who carefully weighed the reasons to continue fighting and found them wanting, but who did, because his brother asked him to, choose to continue to fight anyway. It may not play out that way through the season, but that's what I saw last night, and for the first time in a long time, I felt like both brothers got to clear the boards and show what really drives them -- and guess what?
It's still love for one another.