Pluto also designated 134340 Pluto, is the second-largest known dwarf planet in the Solar System (after Eris) and the tenth-largest body observed directly orbiting the Sun. Originally classified as a planet, Pluto is now considered the largest member of a distinct region called the Kuiper belt. Like other members of the belt, it is composed primarily of rock and ice and is relatively small: approximately a fifth the mass of the Earth's moon and a third its volume. It has an eccentric orbit that takes it from 30 to 49 AU (4.4–7.4 billion km) from the Sun, and is highly inclined with respect to the planets. As a result, Pluto occasionally comes closer to the Sun than the planet Neptune does.

Pluto and its largest moon, Charon, are often treated together as a binary system because the barycentre of their orbits does not lie within either body. The International Astronomical Union (IAU) has yet to formalise a definition for binary dwarf planets, and until it passes such a ruling, Charon is classified as a moon of Pluto. Pluto has two known smaller moons, Nix and Hydra, discovered in 2005.

From its discovery in 1930 until 2006, Pluto was counted as the Solar System's ninth planet. In the late 20th and early 21st centuries, however, many objects similar to Pluto were discovered in the outer solar system, notably the scattered disc object Eris, which is 27% more massive than Pluto. On August 24, 2006 the IAU defined the term "planet" for the first time. This definition excluded Pluto, which the IAU reclassified as a member of the new category of dwarf planets along with Eris and Ceres. After the reclassification, Pluto was added to the list of minor planets and given the number 134340.

Source: Wikipedia

Though Pluto is now officially not a planet in the solar system, many disagree and argue that it a planet for the guidelines were unjust and decided by the minority of the astronomical community (IAU). What are your opinions on this?

As far as this topic is concerned, we still don't know what's it's really inside of it, which would completely disprove that pluto is a planet - but as far as it goes, Pluto is about to get kicked out from register of planets...

Officially, Pluto is not considered a planet now as it has been kicked out from the system of planets in the year 2006 during the International Astronomical Union (IAU) conference. They do have any idea what Pluto is made up of, which is icy bodies. However that is not the reason for annexing it out from the "Planet" category. Instead, an object is considered a planet only if they are able to dominate around its orbit. To do so, the planet needs to be large and round enough and be able to orbit around the Sun. If, we're to follow the old definition of a "Planet", Pluto and its moon (Charon), would qualify as planets.

After many debates, Pluto now falls under the category "Dwarf planets". It's another man-made category where all round objects that have fail to clear their orbits enter. I feel that for now, Pluto is not a planet for I do see many other objects entering the "planet" category if the old definitions were to be used. In my opinion, the new definition of a planet is only but temporary for definitions are man-made and Science is always progressing. In the past, Pluto was a planet, now it isn't. It might become a planet in the near future if the definition changes.

Furthermore, the current definition has it's loopholes too for Mars and Earth cannot possibly have cleared their orbits as they're surrounded by asteroids. Hence, challenging the current definition where a planet has to clear its orbit. Also, there are many debates with regards to the IAU for many scientists were absent during the conference when the decision to rule out Pluto as a planet was given. Many scientist thus view it as a decision made by the minority in their community as the IAU representatives are the minority with power to make decisions (think government and the people; where the government is the IAU while the people is the whole astrological community).

But for now, I reckon that the current definition is the most suitable for it's better than not having a definition at all. What do you all think?

I'd like to keep Pluto around for old times' sake, I'd rather not get into the technicalities because I'm totally novice in astronomy. But that ruins the liberal part so yeah...