OK. As some of you know, "Supernatural" had a forum at the William S. Paley Television Festival. I found a blog, and I passed it to some of you.
But, one thing that wasn't in the blog (and it was reported by a couple of other audience members) is that Kripke stated that the fact that Dean's eyes started bleeding in "Bloody Mary" is significant, and it will be addressed in an upcoming episode (or episodes.)
So, obviously Dean has some sort of secret which causes his eyes to bleed. And it's more than the fact that Mary got out of the mirror (because if that's the case, it wouldn't be addressed again).
What do you guys think Dean's secret is? I have my own theories, but I want to know what you guys think.