GOD FUCKING DAMNIT THEY KILLED MEG? WHY?
Congratulations, show. You fridged yet another female character who was actually interesting and had been around since S1. I get it, she was evil and everybody dies yadda yadda, but she was a cool antagonist who had a pretty complicated history with Sam and Dean. And the worst part is I was afraid they were going to bring her back to kill her, but after she had that little moment with Castiel, I just fucking KNEW that she was going to die, because we obviously can't have any character with lady bits 'getting in the way' of certain pairings, which, by the way, will never, EVER be canon, no matter how loud shippers are. I don't know whose fault that is, the fans' or the writers', but it's so, so frustrating. UGH.
As for the rest of the episode, I thought it was good. I didn't like the Swan Song redux scene and I'm obviously pissed off that Meg died, but other than that I enjoyed it. It was pretty tense, Dean and Sam had good scenes together and I love that they mentioned Meg possessing Sam. And Dean finally knows what's up with Sam -- that final scene was just perfection. :)