I don't think that I can actually comment much about this episode. Of course that's not to say that I can't comment at all.
I loved all the shoutout to the fans. The whole Sam girls, Dean girls and slash fan thing was hilarious! The fan with the tattoo on her butt was interesting. And I really appreciated the way Sam showed his tattoo. And Dean too (but that was mostly because of his facial expression)!
Ok. So the whole Prophet and "Winchester Gospel" thing was ridiculous (Heh. Guess we do complain quite a bit. LOL.) but overall I'm still fine with the episode. But the brothers can never EVER start a sentence with "It frustrates me..." again. They sounded like they were in couples therapy! I laughed but still it's a no-no.
Oh, of course the names used in this episode. Carver Edlund. Kripke's Hollow (I didn't notice that until someone pointed it out!). Phil ("Did Phil put you up to this?"). Simpatico (Well, I don't know about this but apperently it's a real screen name on TWoP).
It's nice to see Cas becoming much more humanized. Dean's a bad influence on him. Lol.
Edit: Doesn't Dean's (and Sam's) full frontal should be taken off if the books are gonna become a gospel?!