Eh, I'd say it worked out pretty well for him in the end. Dean is a far more rewarding and challenging character than Smallville's Clark has been or ever will be.
Can't argue with that. Dean admitting that he'd enjoyed torturing the other souls in hell after he finally got off the carving rack? Wowza.
Don't think Welling would have quite been up to that, but he has more of a Superman/Clark Kent "look," I grant you that.