Did that actually just happen?

So, wait, SPN-watching people. Did Castiel seriously go dark and become a god because Dean didn't love him enough? Because that's what the internet and youtube videos with clips of the season finale are telling me, but maybe it's less "You drove me to this by not having enough faith in me, Dean. Love me like I love you! Your god commands it! LOOOVE MEEEEEE!" in context?

Do Gamble and Kripke have any desire to write for Marvel or DC some day? Because that plot would be right at home in comics.