Will they ever make up their mind, the poor planet doesn't know whether it should be coming or going.
A few years back we were all shocked to learn that, thanks to its size and orbit, the International Astronomical Union had decided to downgrade poor aul Pluto to a mere 'dwarf planet'. Harsh as it seemed at the time, we assumed they knew what they were at, but it turns out they've decided to change their minds on the whole thing and promote it back up to the Planetary Premier League.
Recently, astronomers at the Harvard-Smithsonian Center for Astrophysicists (HSCFA) decided to have a debate on the issue of what exactly a planet was, and they even had a vote on the matter. The main argument against Pluto was that if they bump it back up, then they may have to start including similarly shaped small objects in our solar system, and according to 2Paragraphs.com, that could mean the number of planets would rise to nearly 25, maybe even as high as 100, depending on the definition.
Obviously, that would make the whole 'My Very Educated Mother Mother...' mnemonic a much longer sentence, but the audience of planetary-study-type-people decided that wasn't the strongest argument for keeping Pluto down, so after nearly eight years spent wandering (little Greek/etymology joke there for you) in the planetary wilderness, she's back, baby.