The New Horizons Spacecraft is scheduled to whiz by Pluto around 2015, and my understanding is that it is going to do exactly that — whiz by it.
Where will it go after that? Or what else can it do once that mission is completed?
There are plans for encounters with Kuiper Belt Objects (KBOs) after it passes Pluto. (Pluto itself is a KBO.)
Quoting the New Horizons Mission Timeline:
The "one to two" is a limitation imposed by the amount of available fuel.
The tricky part (well, one tricky part) is finding KBOs that New Horizons can visit.
And the project is asking for help from the public to find suitable KBOs. It turns out that the human eye is better than computers at identifying potential KBOs in photographs. You can help by visiting http://www.icehunters.org/.
How cool is that?