In my opinion, yes he has. Dalton and the Bengals were declared by many people in the preseason, "the worst team in the NFL." Cam Newton is a very good QB, but he has two Pro Bowl running backs and a star WR. The defense is decent enough to win games. Dalton has a very young supporting cast and a defense that is getting a ton of TOs.
People want to get caught up in stats saying Cam is a duel threat and can only go up. However, the way Dalton is playing and leading that team and having a chance to even win that division is remarkable. Dalton should win the Offensive Rookie of the Year just off that.