I think we are just seeing Dexter getting into the zone, hitting his prime as a serial killer. I think its setting up The Ripper as the next big bad but wont happen until season 2. This season is all about Dexter getting settled into New York, dominating a group of sub-par serial killers with his experience and skills, while re-connecting with his son, evading Batista, and dealing with Claudette who appears to be the wild card of the season. The season finale will likely be dealing with the fallout of Batistas hunt, Claudettes hunt, and whatever ultimately happens with Prater. I think Prater will become an ally of sorts. I also think its possible that Claudettes obsession with the Ripper is going to lead her to seek Dexters help in catching him, even if she ends up believing Dexter is the Butcher by end of season. I think they are setting up her obsession as clouding her judgement for a reason; shes more interested in solving the Ripper case even if it means working with another killer to do it.