I agree about the big dark dive and I hope the writers don't pull the punch at the last minute because it's Sam. I also want to see some justification for Dean's fears because otherwise it'll turn out that Dean really has been holding Sam back and that's got to change the tenor of the show. I see Sam going dark but the only thing keeping him from falling completely is Dean and yes, Season 5 will be redemption for Sam, reconciliation between the brothers and hopefully some sort of satisfying conclusion and yet OH, I don't want the show to end next year!!!