Hi Eric, I started following you on G+ after seeing your recent CNet article on Pluto dragonscale terrain. So since you are obviously into some sci-fi, I thought I would share my great theory of the mystery of Pluto! Maybe you can work it into a line of investigation or speculative writing!
First the relevant facts: Pluto has a large and unsustainable atmosphere, Pluto shows signs of geological activity, Pluto's surface has areas covered by organic materials aka tholins. Tholins feature primarily C-N bonds though C-C bonding is also considered probable. Fullerenes, among the champions of C-C bonding have been detected in various interplanetary settings (we know they are present). At very low temperatures (liquid nitrogen temperature), fullerenes exhibit superconductivity. The solar system is permeated by magnetic fields of varying strengths. A conductor passing through a magnetic field has induced current.
So in the tradition of Accelerando, by C. Stross, maybe Pluto builds up a big surface current in the tholin layer from time to time. Conditions in the layer periodically (waves hands in air) cease to be superconducting and then the big current is quickly spent in a surface-wide heating event. The surface undergoes upheaval, a big envelope of atmosphere forms, and then it all settles down again. New Horizon just missed the big show.