Yes. I was reading (http://news.sciencemag.org/space/2014/06/hubble-telescope-lo...) that they got a bunch of Hubble time to look for Kuiper Belt Objects to target after they swing by Pluto. They need to know now so they can get the gravity assist correct.

Given the lack of complete knowledge about the mass distribution of Pluto-Charon system, that must be a hell of a hard problem.