Just when I had given up hope (due to misleading news coverage that suggested the round=planet proposal was a fait accompli), the IAU finally made the right choice regarding Pluto. The additional criterion (missing from an earlier version of the BBC report) is that a planet must have "cleared the neighborhood around its orbit." I had been hoping for requiring that it possess the majority of the mass in its orbital region, but anything that gets us down to the eight bodies with shared origins and finally excludes the Kuiper Belt is okay with me.
My interpretation is that, faced with solid evidence of the absurd results of crafting an objective standard that allowed Pluto to be commonly referred to as a planet (even the proposal separated the 8 "classical" planets from the "plutons" (bizarrely including Ceres)), only the most sentimental of the scientists could bring themselves to support it.