Some good info here.
There are others… The Minimalists, Leo at Zen Habits… a colleague of mine, @markatkayak remarked, "Those blogs had reached a critical mass of sorts. They were receiving so much interaction that they felt it was detrimental to their success. Trust me, this is a great problem to have! If you reach this stage, you're doing a lot right."
My recent post 3 Issues that Can Make you Hate Twitter