This may be a spoiler, depending on how the character is introduced. But it's the kind of "spoiler" that's impossible to avoid if you read the TV trade sites.

I haven't read anything about the other recurring characters for the season. That quote makes it sound like one of them will be revealed as the "true" psycho of the season, with Hank's character being a sort of red herring.
Colin Hanks seems like a great choice for Dexter's foil. Hopefully TVLine is intelligent enough to tout Hanks only if his character being a psycho is handled like Trinity and not the Ice Truck Killer - not a secret that's revealed a ways into the show. Of course the simple addition of an actor like Hanks to the cast is a strong indication he's the season's guest psycho.Colin Hanks has landed a role most actors would kill for. Sources confirm to TVLine exclusively that the Good Guys star Mad Men alum is joining the cast of Dexter for a major Season 6 arc.
If Hanks turns out to be an adversary of Dex’s, it’s unlikely he’ll fit the mold of past baddies such as Trinity and the Ice Truck Killer, given what Showtime president David Nevins recently told TVLine about the show’s coming season. “It is not [about] one big bad,” he told us. “There’s one interesting story that will move through the season, and it will be cast very interestingly, but it’s not exactly that one person.”

I haven't read anything about the other recurring characters for the season. That quote makes it sound like one of them will be revealed as the "true" psycho of the season, with Hank's character being a sort of red herring.