(Arrrg - here I was about to start posting the same thing and you stole it from me... grrrr.)
I can fully understand "them" and the need for classification of objects.
If Pluto was a planet, many other rocks would be as well, as they also mention in the article, and we'd have 12 planets so far in our solar system, and likely many more.
As for actual consequence, well then there isn't really any other then how we define the universe.
Astrologists would likely be the most hit by this (
), but many in Denmark have already said that they would not stop calculating with Pluto because it has a large effect on people. And I'd almost expect such a opinion is pretty worldspread for such a field.