Pluto's diameter is 2274 km. Despite continual, years-long anti-American efforts to downgrade Pluto (it was discovered by a US observer) from planetary status, Pluto remains a planet.
Until now, the next smallest (known) body in orbit around the Sun was 1800 km, or half the volume of Pluto.
I think Pluto should be "grandfathered" in as a planet, with all the attendant privileges afforded to such rank. It did just celebrate its 75 anniversary, after all.
from the discoverer of 2003 UB313, the 10th planet:
http://www.gps.caltech.edu/~mbrown/planetlila/index.html
"From now on, everyone should ignore the distracting debates of the scientists, and planets in our solar system should be defined not by some attempt at forcing a scientific definition on a thousands-of-years-old cultural term, but by simply embracing culture. Pluto is a planet because culture says it is."