"Doubt My Status as a Planet, Will You?!" - Pluto

Hubble has confirmed that New Horizons will have more to look at than just Pluto and Charon when it swings past them in 2015. Currently, the two new moons (originally discovered last year) are currently refered to as P1 and P2. I'm thinking they should eventually be called Cerberus and Proserpina (or Persephone). If they want to save Proserpina or Persephone for a planet, Styx or any of the other rivers of the underworld would be good, too.