Long ago, the debate has been open about whether or not Pluto is a planet with the same status as the 4 giant planets - Jupiter, Saturn, Neptun and Uranus - or the 4 earth-like planets - the Earth, Venus, Mars, Mercury. Since the year 2000, when the official list of "minor planets" reached the symbolic number of 20 000 objets (the first object of the list being Ceres... claimed to be the 8th planet in 1801 but a few years after being demoted, for reasons very similar to the ones in the rationale of recent IAU decision), the chase for bigger or heavier objects than Pluto has been open, and candidates were quickly found: Varuna, Sedna, Quaoar and, likely the biggest shot, Xena (2003 UB313). Now scientists wisely consider that Pluto is only the first discovered big chunck of the Kuiper belt, like Ceres was in the main asteroid belt. What is wrong with that ? It's not the first time, and it will not be the last in astronomy, that scientists face the issue of reshaping the popular knowledge (or faith!). For the honor of science and teaching, please stop with lobbying around cultural conservatism (i.e. http://www.plutoisaplanet.com/) and put national pride (i.e. http://www.pleasesavepluto.org/) in the right way: nearly all "transneptunian" - or "plutonian" - objects were discovered by american astronomers, and "New Horizons" is a wonderful NASA project.
N.B. Bon!.. un débat même un peu vif (par ex. in http://www.techno-science.net), n'est pas si mauvais pour développer l' "astronomie populaire" chère à mon maître Camille Flammarion ;-)