The facts

The International Astronomical Union (IAU) voted on an official definition of the word "planet" at their general assembly on Aug. 24, 2006. Celestial bodies must meet the following conditions in order to be classified as planets: (1) The object must be in orbit around a star, while not being itself a star, (2) the body must be massive enough for its own gravity to pull it into a nearly spherical shape, and (3) the object has cleared the neighborhood around its orbit. The last criterion is the one that led to Pluto's demotion. While the exact parameters of "clearing the neighborhood" have not been set, the other planets have either assimilated or repulsed most other objects in their orbits, and each has more mass than the combined total of everything else in its area. The same cannot be said for Pluto, which has turned out to be one of many objects in its orbit.
Pluto is Out!
Pluto's new classification is "dwarf planet," while the eight planets remaining—Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune—are planets. The dwarf planet definition mirrors the planet definition in the first two conditions. The third condition says that the object has not cleared the neighborhood around its orbit, and the fourth states that it is not a satellite. A dwarf planet does not meet the third condition of a planet, but it must meet a fourth: a dwarf planet cannot be a satellite. As a result, Pluto's satellite Charon, briefly considered as a full-fledged planet in the solar system, is back to being a moon. The term "pluton" was rejected and the name for this class will be decided upon in the future.
Others Considered for "Planethood"
The asteroid Ceres (classified a planet when first discovered in the 1800s) and Eris (previously nicknamed "Xena"), both formerly under consideration for planetary status, are now out. Ceres and Eris have joined Pluto as dwarfs. The IAU also has a dozen candidate planets awaiting future designation as dwarf planets, including Sedna, Orcus, Quaoar, Varuna, Ixion—all found beyond Pluto; the asteroids Vesta, Pallas, and Hygiea; and four yet unnamed bodies (2003 EL61, 2005 FY9, 2002 TX300, and 2002 AW197).
Also defined was "Small Solar System Bodies" as all other objects except satellites orbiting the Sun. These include the asteroids, Trans-Neptunian Objects, comets and other small bodies.- factmonster.com

Pluto is a planet

It is true our favorite planet, now gone, evaporated... Pluto! Pluto once the ninth and final planet of our solar system is now officially not a celestial body. What ever that means. I mean come on, first you take away cell phone driving and now a planet! Pluto was always my favorite planet a little guy compared to the rest but who cares? Now a puny handful of scientist decided they do not want Pluto a planet anymore because it is to small! Well fine Rhode Island is not s a state, Vatican city is not a country, for Pete’s sakes mini coopers are not cars. Why does Earth get to govern every thing huh? Why do some quacks on the fifth largest planet get to decided? What makes us in control. Besides I didn't vote for this and chances is you didn't either. So much for Democracy. Now what are all the little mobiles with Pluto going to do? Just be ripped off? So if Pluto is not a Planet then I would like somebody to tell me what it is! Is it an asteroid, ball of icy mass, star, who knows?!?! This is from Dictionary.com: Astronomy. Pluto the planet ninth in order from the sun, having an equatorial diameter of about 2100 miles (3300 km), a mean distance from the sun of 3.674 billion miles (5.914 billion km), a period of revolution of 248.53 years, and one known moon, Charon. See it still believes Pluto is a planet, and who doesn’t some Swedish scientist with Telescopes.
Pluto has been a planet and it always will be!

(follow link for more! http://www.lowell.edu/users/buie/pluto/planet.html)