I have to disagree about the point about Jupiter and Saturn's moons though. They are clearly moons since the centre of gravity is for all intents and purposes at the centre of the planet.

Not if you consider Jupiter and Saturn as stars that failed to ignite (brown dwarfs). That would make those 'moons' planets on a three-star system where our sun is the major star and Jupiter/Saturn as minor stars. Then the centre of gravity of the 'moons' is in themselves as they orbit their minor 'star'.
But that would confuse the major/minor planet debate further.
Ow, my head hurts...