NASA launched New Horizons on Jan 16 2006 and it is scheduled to arrive at Pluto on July 15 2015. Its only a fly By mission meaning that the probe wont orbit Pluto or decent through its atmosphere. It will merely take pictures and other data while it passes by.
No other Probe/spacecraft has ever been to Pluto before. Depending on the success of the Pluto fly-by and several other factors scientists might include mission to observe other dwarf planets and kuiper belt objects beyond Pluto.