It's currently considered a dwarf planet. It's very small in comparison to all other known planets in the solar system. The composition of its surface is primarily ice with a core based in silicates. These two statements show it is in fact a dwarf planet, a classification created specifically because of the study of the planet.
It should NOT be a planet. There is absolutely no logical argument for making it a full fledged planet. It's nothing more than another piece of debris in the Kuiper Belt. It only makes up about .07% of all the mass in it's orbital path. Earth, for example, is 1.7 million times the mass of any other object within our orbital neighborhood. Making pluto a planet would be like making a large asteroid in the asteroid belt a planet. It was classified as a planet when it was discovered ONLY because there was NO "real" definition of the term "planet". It wasn't known at the time that the Kuiper Belt existed, nor that there were a lot of other smaller objects about the same size within it's vicinity.