A new verb is making its orbit: to pluto

The phrase to pluto someone means “to downgrade, demote or remove altogether from a prestigious group or list, like what was done to the planet of the same name” [1]. Pluto's demotion took place in 2006, when the International Astronomical Union (IAU) (re)defined the term “planet,” putting Pluto on dwarf planet status [2].

While considered to be planet after its discovery by the American astronomer Clyde Tombaugh in 1930, Pluto was named by Venetia Burney, an eleven-year-old schoolgirl in Oxford, England. Thereafter, planet enthusiasts had a prestigious list of nine planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. If you want to see all nine orbiting around the sun, there are animations and tours available [3]. By the way, the laws of (astro)physics do not change by shuffling classification schemes and conventions—and no tears, Pluto is still a planet, just a minor one along with the asteroid Ceres and trans-Neptunian objects (TNOs) such as Eris (which is 27 percent more massive than Pluto), Haumea, Ixion, Makemake, Orcus, Quaoar, Sedna, Varuna and other fascinating objects.

Let's put it together in a limerick (Axel Drefahl, November 2011 ):

Once upon a time,
planets there were nine.
But Pluto lacks in weight:
now there are only eight.

In case you are looking for more than a summarizing rhyme: there is no better way to learn about highlights, details and the downfall of Pluto by reading Neil deGrasse Tyson's book The Pluto Files [2]. Therein, I also found the link to the American Dialect Society, voting for “plutoed” as the word of the year in 2006, in a run-off against  “climate canary” and in competition with the noun murse (for man's purse, getting zero votes) [4].

Although Pluto has been plutoed, this dwarf planet will get increasing attention:  NASA's New Horizons Spacecraft is currently halfway between Earth and Pluto, approaching the icy little planet and its moons for a flyby in July 2015 [5].

Keywords: astronomy, solar system, minor planet, verb, grammar, linguistics.

References and more to explore
[1] Urban dictionary > pluto www.urbandictionary.com/define.php?term=pluto.
[2] Neil deGrasse Tyson: The Pluto Files. W. W. Norton & Company, New York and London, 2009.
[3] Nine Planets nineplanets.org/. 
[4] “Plutoed” Voted 2006 Word of the Year by American Dialect Society [www.americandialect.org/Word-of-the-Year_2006.pdf].
[5] NASA > Missions > New Horizons www.nasa.gov/mission_pages/newhorizons/main/index.html.