Well I bookmarked this a couple of years ago, I can't remember if it has the date or not, but give it a read, it probably contains your answer. http://www.space.com/scienceastronomy/060824_planet_definition.html
Well the reason they don't call it a planet anymore is because it's just a solid ball of ice. There's no land mass, no life, no nothing, just a solid ball of ice.