So is Pluto a planet after all?

The news last week that Eris might actually be a tiny bit smaller than Pluto led to the inevitable question: doesn't this mean that Pluto should be a planet, after all?
The simple obvious answer to this question is no. Pluto was not demoted in 2006 simply because it was no longer the largest known object beyond Neptune, but because it was one of many many such small objects beyond Neptune. The