re: Maybe...
Pluto is a very dormant comet now.
Pluto may be a cousin of Neptune's moon Triton and possibly, Uranus' Titania and Ariel to name a few. From images of Pluto taken by Hubble, they share the same coloring and composition (mostly ice/Nitrogen) and even 'volcanic' activity.
More on Triton: http://voyager.jpl.nasa.gov/science/neptune_triton.html
http://www.solarviews.com/eng/triton.htm
The Voyagers couldn't catch Pluto, but they did very well.