So, um, there's this debate about... what exactly constitutes a "planet." Who better to decide than the IAU - that is, the International Astronomical Union (filled with officialness)? And what of Pluto? The Planet Definition Committee, formed by the IAU, has come up with a proposition. It's got to be a certain size, orbiting the sun, and round. Why round? It has to be large enough and have enough gravity to shape itself into a sphere. So what does this mean? Pluto is a planet. However, it's "moon" Charon is also a planet. Thusly, Pluto-Charon is a double planet system. It's a bit technical why Charon is and Earth's moon isn't, but I won't go into it. This also qualifies the biggest and thus first discovered asteroid Ceres as a planet, as well as a farout Transneptunian body, tentatively called Xena (this nomenclature is also pending IAU approval). How would you like that, a planet named Xena? Bodies such as this would be known as plutons (ah, Pluto has started a trend) while bodies like Ceres might be called "dwarf planets" for differentiation from the larger well-established planets we all know. There are further candidates that will be explored by the IAU to perhaps be classified in these ranks or sentenced to the dismal realm of "Small Solar System Bodies."
I don't know about you, but I'm excited. And yet, not because to me, it doesn't matter as much what name is tacked on an object, we're still going to explore all of these objects. But then I love to classify and sort stuff, and it does sort of prioritize what might be investigated. Anyway, it is very interesting to see this happening formally. And what other planets might we gain?reference
Also, I will update all about today as soon as I have time and energy.