Would you post some of your theories?? Because I'm going nuts not knowing what to think!!!
Personally, I think the amulet's coming back. There is some part of me that is definite about this. I don't know why, but it just seems like too perfect of a set up for it not to come back. Cas is God. The amulet finds God. The boys are going to want to know where Cas is. TA DA.
I also am thinking they might retroactively make Dean/Jo canon, which I'm not really happy about because I liked their relationship as is, but I'm really happy that they're not legit bringing her back, because her death was heart-shattering and I'm glad they're not going to cheapen that.
The only thing I'm confused by is that we're apparently going to see Dean and Sam separated more this season, which...I can see how, without Sam's whole wall thing, would be interesting and feasible, seeing as they're at a way more stable place in their relationship now and ready to grow more individually and have other relationships (even though they still love each other just as much). But with Sam going through what he is, and it possibly being permanent? I can't see Dean being anywhere besides by Sam's side. I don't know how they're going to do that. Maybe have Dean on solo hunts, with Sam at Bobby's and incapacitated? But they took down the set for Bobby's house...and how are they going to incorporate them both equally if they are separate?
Sorry, this turned into more of a thinking post than a theories post, but with all the new spoilers I'm a mix of confused/apprehensive/excited, so I'm not really coherent.