Oh, where do I begin???
THOSE BASTARDS HOW COULD THEY END IT THERE?!
AAAAARGH!
*calms down*
First off, I loved the parallels they kept drawing between the two Winchester brothers. By this I mean how they would have one scene occur with Sam and then have that same scene reenacted by Dean, but with a different ending. For example, you first had Sam and Ruby discussing the future of the relationship between Sam and Dean. That scene ends with Sam believing that the rift between them can never be healed. Then the scene switches to Dean and Bobby who are also debating the outcome of the relationship between Sam and Dean. This discussion, however, ends with Dean realizing that the relationship between him and his brother can indeed be mended.
These "parallel" scenes continue to occur throughout the entire episode, and each scene ends with Sam and Dean having the same conversations or going through the same actions but coming to completely different conclusions. I wonder what this says about the character growth that they've gone through at this point.
Also, I loved how they tied the season finale to the season premier by not having any music.
Zachariah's revelations about the Angels true intentions weren't that surprising. At this point I would have been shocked if he was a good!Angel. Speaking of which, I was so very impressed by Castiel's actions in this episode.
Castiel completely redeemed himself by doing what he felt was the right thing. It was interesting to watch because Castiel and Dean both came to the same conclusion and thus achieved the same character growth - almost in unison. Dean's realization that he didn't have to take orders from anyone [be it John Winchester, Zachariah, or God] triggered the same realization in Castiel and then together they decided to change their fate and possibly the fate of the world.
I did enjoy watching the newlyweds get into their first "married couple" argument and then have makeup sex shove each other up against a wall and draw blood sigils. I let out a "WHOOP!" when Castiel banished Zachariah.
The scene with Chuck was awesome in so many ways. Particularly the part where he was ordering prostitutes for his last night on earth! Ha! GO CHUCK! He also had one of the most important lines in the episode, "You're not part of the story." I think that says a lot about destiny and how free will has the ability to change it. Cas and Dean are going off of the Heavenly script and who knows what they'll accomplish!
When Castiel told Dean, "I'll hold them all off," my heart stopped. He was willing to stay and fight an Archangel and basically hold off the hordes of Heaven so that Dean would have a chance to save Sam. That was an immensely powerful act on his part and it just demonstrated the depths of his devotion to Dean.
That said, I'm not convinced that this Archangel guarding Chuck is a bad guy - I guess we'll see.
I also liked how we heard the voice of Lucifer, that was so very creepy. But it also means that since we've heard the voice of Lucifer that we can eventually expect to hear the voice God.
Another thing to note is that they made sure to state that Lucifer was an angel and angels, unlike demons, can only possess those with a particular "something" in their blood - they need a vessel. I think then that we can infer that Lucifer ordered Azazael to find him a special child and make it so this child's blood, body, and mind can support being Lucifer's Vessel. Sam is then the Vessel that Azazael created for Lucifer.
Speaking of Azazael and well laid plans, I adored the last 5 minutes of Ruby's existence. She played a perfect hand and, yeah, that was pretty awesome. If I were ever in her situation I would have done exactly what she did. I mean, she was still pretty annoying, but her plan was flawless and it succeeded. I was impressed.
The ending left us with a ton of cliffhangers.
What happens to Cas? We know that he survives somehow since he's a permanent character for the next season, its just a question of how he survives. I expect that now that he has renounced Heaven, he'll be spending more of his time with his husband Dean trying to stop the Apocalypse and whatnot.
Then there's Anna. We know she was carted off by the angels - but there were the spoilers that say she was going to give Dean some of her angelic power. So one of two things might happen, we never hear from her again or she shows up and gives Dean her powers. Ether way, we wont be seeing much more of her since the actress has a lead role in a new series.
The big question is: what will happen with Sam. Obviously, he's realized that he was being used by Ruby. I hope that his realization came in the nick of time to save him from becoming either a demon or Lucifer's vessel but it's doubtful. Personally, I was shocked to discover that Sam's downfall was not caused by his demon blood but by his own, human, personality. I imagine that this fact sits poorly with many people who were hoping that Sam's bad decisions and abhorrent actions were caused by his demon blood. So where does Sam go from here? Can he be redeemed?
As for Dean, I think his fate is the clearest of all, he's become his own man and he's going to stop the Apocalypse and save his brother. God help those who get in the way of the Righteous Man.