Warning: Spoiler Alert
So, it looks like Dean is going to go the route of trying to live with the Mark, instead of constantly trying to get rid of it. I think that would be great, if it wasn't something that probably wasn't going to be a constant struggle for him to accomplish ... but he may do a better job of keeping it under control than Sammy would; maybe the way to make sure that the Mark doesn't make someone go completely out of control is to make sure that the person who has it is already someone who is beating themselves up over something, and is someone who already knows what it is to struggle with something. Maybe you need to be someone who isn't well adjusted to make the struggle work? Yeah, he's already gone all dark side with it, but maybe that was only cuz he had died and the thing brought him back (so he came back a demon, instead of himself).
I wonder if the writer of this episode thought s/he was being clever by making the initials for the fraternity be "STD"? Maybe it was just me, but the joke seemed incredibly juvenile and not funny. Far too much in the way of "college humor," as it were ... but maybe that was the point (seeing as how the episode spent so much time on a college campus). Still, I had the feeling that we were supposed to find more humor in it than I did (which was pretty much none at all).
And this whole, "Dean doesn't know anything about modern technology" trope that they've been riding for a while now is getting kind of old. Dean may not be as tech savvy as Sammy is, but there are things that he should know about (like that nothing can really be deleted off the internet (especially that one, since they use the internet for research so very, very much), or whatever the writers happen to be calling Siri in the show, since you don't have to be using a particular brand of phone to know about phone aps that can speak to). Also, I guess we're going back to the trope of having Dean being the one who eats all the time, while Sam just sits there and watches him do it? That one is getting kind of old as well, especially when they have Jensen kind of go over the top with it, and have noodles hanging out of his mouth.
It looks like we're going to see the return of Cain in the next episode, and I'm actually pretty happy about that. But with Dean seeming to come to terms with the idea of having the Mark, I'm not completely sure that we're going to see the end of the love affair that is Dean and the Mark. I'm getting the feeling that Dean is going to see Cain go kind of crazy with the return of the First Blade, and he's going to decide that maybe it's time to keep good on his promise to kill Cain when he had the chance (so, he'll end up having to keep the Mark, unless he wants to curse some poor sucker the same way that he was). So, yeah, I get the feeling that the writers are going to take Cain and the ability to get rid of the Mark out of the equation.
Kind of makes me wonder what would have happened if Dean had become the vessel for Michael. Would he be able to even have the Mark if Michael was riding him? Probably not (and he probably wouldn't have even needed the Mark in the first place if Michael was there ... but then, that would mean that he was stuck in the Pit with Lu and Michael, the way that Adam is), but it would have been kind of interesting to see the conflict that would have come about from something like that.