Pluto-Charon is a dual-planet system much like the Earth-Moon system. Regardless, Charon is still a moon as it orbits Pluto, likewise, the Moon is still a moon because it orbits Earth. Had these moons been in seperate orbits they would be considered planets, along with the Galilean Sattelites, Titan and Triton.
As for planets, I was a solar system nutcase back in the day. I memorised the names of the planets without the use of mnemonic, along with diamater, surface temperatures, Number of moons and distinguishing features.
I'm probably a little bit out of date by now but I still recall some interesting tidbits, for instance, Maxwell Montes is the second highest mountain in the solar system, resides on Venus and is one of the very few features of it's surface named after a male. Neptune had it's own gigantic Hurricane, the Great Dark Spot and Triton is one of the few places in the solar system where Cryovolcanism takes place.
As for these paltry new additions to the planetary family, they're like the red-headed stepchild thrice removed. It all ended with Pluto
