Looks like Pluto planet-ness continues to degrade:

Dwarf planets accumulate in outer Solar System

PLUTO’S STATUS MAY TAKE a further hit, say Australian astronomers, if around 50 neighbouring space objects join the ranks of the dwarf planets.

Pluto was demoted to ‘dwarf planet’ in a decision by the International Astronomical Union (IAU) in 2006. This decision – which was unpopular with the general public – was based on the discovery of many objects which were a similar size or larger than Pluto in a zone of the Solar System known as the Kuiper Belt.

Other dwarf planets include Ceres, the largest asteroid in the rock-strewn belt between Mars and Jupiter, and four Kuiper Belt objects: Eris, Makemake, Haumea and Quaoar.

Now, astronomers Charley Lineweaver and Marc Norman, from the Australian National University in Canberra, say the definition of what it means to be a dwarf planet should be revised to include many smaller objects too.