I
know that Bobby is back for the final three episodes of this season. There is some really strong stuff there were Dean and Bobby are trying to get Sam to kick his demon blood addiction. There is some really powerful stuff in the relationship between the three. As to how things wrap up? Well, when you are a character on Supernatural, you can get killed and come back. When you are an actor on it, and you spill too many beans, they can kill you and you don't get to come back.
From Movieweb interview
According to a highly reliable inside source, fans hoping the third Winchester is some kind of trixter manifestation or easily undoable Kripke mind-frak - sorry! The word is that the new Winchester, Adam, is the real deal. How solid is this intel? 99.9% Probable. That leaves a meager margin for the incredulous to cling to. Now here’s the thing. The source says that while everybody may be focused on whether or not Adam is legitimately John’s illegitimate son, come Friday morning we’ll be talking about an entirely different wrinkle in the Supernatural drama. Look for a twist ending that strikes from north of nowhere.
From TVOvermind.
BOOO to the Jump the Shark spoiler. :-P