They orbit each other, but not symmetrically, I don't know how things are in reality, but by looking their masses ( heavier star has a mass of 11 sun masses and the smaller one has a mass 7 sun masses), their common point of gravity is near the heavier star, so heavier star makes a smaller orbit. Like if you put a weight of 11 kg on the one end of stick and a weight of 7 kg on the other end, you have to lift it near heavier weight to keep it in balance.
Also, in a few days NASA is going to lauch a fastest probe ever, New Horizons will explore Pluto and other Kuiper Belt objects. Now it looks like the lauch is going to take palce January 17th. After the lauch probe will reach Moon's orbit in just 9 hours (it took couple of days for Apollo spacecrafts to reach Moon) and the probe will travel as fast as 21 km/s (47,000 miles per hour), but it still takes 9 years to reach Pluto, flyby is expected to take place 2015.
Website:
http://pluto.jhuapl.edu/