citrusjavaJust based on the Js' expressions when they try to smile after shooting, my money's on the season ending so horribly - possibly Dean actually killing Sam this time. I'd say - Sam doing it so Dean doesn't - but I'm more convinced that that mention of Lucifer wasn't accidental, as Sam's self sacrifice and darkness goes.
Something truly horrinble.
*makes sandwich board urging passers by to stock up on fluff *
[IDK anything concrete, so please no spoilers ]