I admit I'm a little tired of angels and demons arcs at this point, so that's probably why I just didn't care about the plot all that much -- I didn't hate it, but I didn't love it either. Besides, I get what they were doing, but I thought it was somewhat anticlimactic that they spent most of the episode trying to get Samandriel out only to have Castiel kill him. Having said that, now I am more curious to know what exactly is going on in Heaven. Naomi is scary!
It was nice to see Kevin again, too. I like that we got a bit of an update on how/what he's been doing, even if it didn't add much. I feel like sometimes they go too long without dealing with certain storylines, so that was cool.
And are we really done with Benny and Amelia? Somehow I really doubt that. This is only speculation, but my money is on both of them making a comeback at some point later in the season, with Benny going bad and Amelia being used by someone to get to Sam.
As for Sam and Dean... where do I even begin? I think it was fairly obvious that they wouldn't be separated for long, so I wasn't surprised at all that they both chose to be together, but it kind of stung that they seemed so damn miserable about it. At the same time, their relationship has been so strained lately that I don't think I would have bought it otherwise, so I guess that made sense. I mean, it's not like anything major happened and left them with no option but to be together, and I actually liked that they both stopped trying to push the other in a particular direction.