I liked the episode a lot, but it did feel a little off. I'm not sure what it was though.
It seems like they're cranking up the mythology of the show. As the promo said they seem to be leading up to the End of Days, and upping their game with the threat level.
I have to wonder if Castiel is playing Dean though. Lightning, dark shadows, burning the eyes out of people who are possessed rather than banishing the demons etc. seem pretty dark for an angel.
The devil/Lucifer is also an angel, could he not be pulling this stuff, too? Sam was only supposed to lead Yellow eyes armies, perhaps Dean will be ending up doing the devils dirty work, and cleaning up these upstart demons, such as Lilith?
Not that I have any objection to it being true either, I just think it could be they both think they're doing good, only to turn out their both paving their own road to hell.