what does this mean?
It's obviously not just a neat effect, the episode made a point in the teaser of reminding us the eyeball scorching impact of a human looking upon an angel's true form. And Dean being able to gaze on Zach comes hot on the heels of him being able to kill the Whore of the Week, a job supposedly reserved for "a true Servant of Heaven".
Some people have harked back to Uriel's only an an angel can kill an angel statement, but i am not sold on the veracity of that. I mean I doubt Cas would've armed Sma adn dean with angel killing swords if that was so.
So what's your theory? has Dean got some angel in him? *koff* Cas *koff*