I may be a rare bird with this idea but please bear with me. How I handle it when someone follows me, I follow them back. The problem is, once they unfollow you, you have know way of knowing if they did so other than digging through the list. Is there some way it can be made as an option in the settings to automatically unfollow those that unfollow you?
I know it sounds like an odd request. I view (lightly) followers as friends. It's quite humiliating to leave comments on their blogs not knowing they want nothing to do with you.
Like I said, it would only be an option to each wordpress user should they decide to tick the radio button. :)