Sidechain, from what I understand, their only intent was defining bodies within our own solar system. Meaning that the new definition is just a qualification of our own plantery group.
We have had a recent boom in the location of Kuiper Belt objects that challenge the old definition of Planet. Pluto's discovery came out of the search for Planet-X, the thing that causes a weird gravitational tug on the system. Now I think they are realizing that it's not just one mass, but a host of massive forms causing them to rethink our own celestial course as it is defined by the gravity of distant objects.
