Honestly those two died and sacrificed themselves for each other plenty of times. Would be nice to see the show end with both of them alive somehow
The dude who plays sam says he sees no way for the brothers to live. They have to die once it's all said and done(Obviously for the greater good)
Also while i do hope the demon dean storyline sticks around for a while it's known he's gonna revert back to normal dean at some point. I just hope he stays demon dean at least til the mid season finale. And then the 2nd half can be Dean/Sam/ Hunting down crowley and finally killing him.
What i think is going to happen is Sam is going to cure dean. Thus completing the trials. Which means sam is going to die. But Cass is going to use the last of his grace to heal sam. This is really gonna effect Dean because he's the reason Sam had to cure him in the first place. So he's gonna take that out on Crowley.
So Cass is gonna die by the end of the season with sam/dean being 100% again while the gates of hell are finally closed and Crowley is dead.
I just have no idea where Metatron fits in all this. They should of just killed him.