New Horizons is a very high-tech, small, roughly 1,000-pound spacecraft with the most powerful battery of scientific instrumentation ever brought to bear on a first reconnaissance mission.
I think that one of the things that will come out of the New Horizons mission is that the public will take a look, and they won't know what else to call Pluto but a planet - and a pretty exciting one.
In the mind of the public, the word 'planet' carries a significance lacking in other words used to describe planetary bodies... many members of the public assume that alleged 'non-planets' cease to be interesting enough to warrant scientific exploration.
Discovering that our solar system has many more planets than we ever expected, and that most of them are ice dwarfs rather than like Earth and the other rocky terrestrials, is just another step in the revolution in viewpoint that removed the Earth from the center of the physical universe and makes Earth all the more special.
In science, we take large numbers of disparate facts and reduce them to see patterns. We use the patterns to reduce the amount of information. It's the reason we name species and genera and families in biology. It's also the reason we have names for certain types of geological features and so on in other fields.