1. Jared is not Dean. He's Jared Padelecki.
2. There is nowhere else for Dean to go. They destroyed, beat down, castrated the character. The systematic destruction of Dean started with the arrival of Jess, and continued even after Jess left. Dean fell to the curse of Rory Gilmore. I liked Dean, but I liked the Dean who had a passing knowledge of literature (he said Rory should read Hunter Thompson), not the one who only cared about Battle Bots, just so they could emphasize Jess being a reader. I liked the Dean who gave Rory the most beautiful smackdown breakup ever at the marathon, not the Dean who pathetically on the night of his freaking bachelor party whined that Rory O'Hara is "the one." I liked the Dean who refused to fight with Tristan at the dance and could tell Rory that Tristan liked her without getting bitter, who thought Rory wasn't interested in him in Cinnamon's Wake, and was willing to leave her alone, who made the bracelet, who Rory initialized their first making up. I can't stand the Dean who married someone he wasn't in love with, who cheated on his wife, who thinks the sun shines out of Rory's butt, who is so bitter and nasty that he tries to cast doubt on Luke's relationship with Lorelai.
And, if he came back, you know his storyline would be about Rory. He would be nothing more than a satellite orbiting around the celestial wonder that is Rory Gilmore. No thank you. I don't watch Supernatural, but I hope Jared has a chance to play a fully realized character that isn't latched on to another one to show how super amazing they are.