(Sob) Pluto is no longer a planet. Not as defined by international astronomers anyway. There was a resolution to include it, plus Charon and Ceres in a pantheon of twelve. That's been scrapped. A planet is now a body pulled into a roughly spherical shape by its own gravity that has cleared its orbit round the sun (except of course for any moons it has collected in the process.) So that means an octad of planets: four rocky dwarves and four gas giants.
Still, all is not lost; Pluto now becomes the first, and nominative, member of the class of objects known as Plutonian bodies. And there's already more of them than there are planets.
The status of Pluto is really a fuss over semantics. It doesn't change in the slightest the structure of the Solar System. We still need to send a probe to study it. It's still by far the closest Kuiper belt object. It can tell us a lot about the formation of our System and its workings.
And now the textbooks will have to be rewritten.