I loved this season, and I'm looking forward to the next season. I love the idea that we're having other humans as the primary adversary going in to the next season.

I'm also stoked about Mary's return. What I'm hoping they do is get into the idea that Sam and Dean (and especially Sam) really don't know much about Mary as a person. Sam would have practically zero memory of her, and Dean's memories would primarily be of Mary as 'mommy.' What they know about her beyond that would all have been heavily filtered through John's perspective. I hope we'll get some surprises from Mary.