I'm firmly of the opinion that Bates killed his wife. Not that the show means us to think that, but that the entire thing makes a lot more sense if he's an amazing manipulator who has them all fooled. The actual solution to the thing made no sense to me at all in terms of motive.
Perhaps the final scene of the series will be Bates dropping his cane and walking out of a police station and like that, he's gone. A la Kevin Spacey from The Usual Suspects.
I love the show. Can't wait for tomorrow's season finale, although I've been spoiled about a certain character. I'll still watch!