I watched the NASA TV news conference live early this morning and they were certainly pretty excited, it's worth watching.
Re the mountains, they are of course made of water ice, but are fairly young (like maybe 100 million years at most) so that indicates that there is/was active geology happening on Pluto. The spectral data is fascinating, with loads of methane, but with uneven distribution across the planet; as well as the water ice, nitrogen, etc.
Obvious to me is that Pluto seems to be an ideal place to process fuel for return trips to the farther reaches of the Kuiper Belt. A reactor on Pluto could melt and electrolise the water from the water ice into oxygen and hydrogen, giving resources for restocking ships with fuel, air (when blended with nitrogen), and water. I can invision Kuiper Belt mining ships calling into Pluto to restock. Sure it's a long way out there, and damn cold, but there is plenty of useful stuff there. And its great to see an abundance of water so far out, which means there is probably much more in the Kuiper Belt (just stick a tractor engine on one object and toss it down to Mars). etc etc
