I posted a bit about this in the other Pluto thread, so I'm not going to unintentionally hijack two of them because that would be rude. Anyone can read my more detailed thoughts there, should they care.

However, I thought it worth mentioning again that the definition does not choose dynamical properties instead of physical; it is based on both. This is how good science is done: by using all the info you've got, not cherry-picking. The definition is not based on 'where' it is, it's based on what it is, what it's doing, and how it got there. That's "and", not "or".

I agree that the way it's laid out is needlessly wishy-washy though. Perhaps it's implicit to most of the planetary astronomers who know what they're looking for, but it apparently looks a fudge to everyone else. We can only hope they revise and improve it in future.