Damn. I watched it last night and next season has to be the last. I don't want Dexter to be dragged out for multiple seasons, ala Entourage. There are so many unanswered questions.
I wonder how the writers will wrap it up with the Mitchells and "Kyle Butler" though, if they even plan to.
I don't think that next season has to be the last. I'd say that they can churn out at least 2 more seasons. I think that there's still a lot of story left to tell.
I was wondering about the Kyle Butler storyline as well. I don't think that the writers are planning on continuing with that storyline. They seem to move on to the next story each season. Maybe, in the first episode, Dexter will mention that the Mitchells moved out of town somewhere or something. I think it would be nice if Dexter sent the Mitchells the money that he took from Arthur, and wrote them a note from Arthur, telling them that they are free and that he'll leave them alone. Something like that.
I still can't believe that they killed off Rita<-major spoiler. That was totally shocking.