OK so I think he might die and Sammy has to save him, like go into Hell and pull him out, Ruby might help. I don't mean like re-open the devil's gate, that would just be stupid, but some how Sammy will save him.
I've read that people think it might be something to do with the necklace which would be good. But I think that the necklace was explained coz the fans kept bugging Kripke about what it meant/symbolised. But would be so good if some thing like that (Sam's love for Dean) ultimately saved him.

yeh i guess, i thought it had somfen to do wf da necklace i just think dat would be to easy though and dean would have known

I think sam might save him!!