The long range camera has previously been able to see Pluto and Charon orbiting (showing how they move as a binary). Article here.
Interestingly, the other moons orbit the binary pair -- in other words they are circling the common center of gravity (barycenter) between Pluto and Charon.
New Horizons has just barely been able to spy Hydra, the next largest object in the Pluto system. Here is a long-exposure time-composite image. Hydra is the little bump just above the Pluto-Charon bright spot. Article here.
Only 10 months until the flyby!