I've completed up to "Something Wicked."
And, my goodness. John Winchester did a major job on Dean, didn't he? Made him practically a second (and more present) father to Sam while making sure that Dean never thinks of doing anything on his own. He does what Daddy tells him (and it *is* Daddy in his mind, not Dad - when he sees John for the first time in Chicago, it's "Daddy".) It's like, he never had a childhood, but he never had an adulthood, either. Which is how he reads, really - an overgrown boy, a permanent adolescent with two drives (maybe three) - take care of Sammy, do what Daddy says and hunt demons. He can barely imagine a different life and doesn't understand how Sam, who grew up knowing nothing else, could.
On a shallower note, they made adorable priests. :)