Not much; a couple of cameras (which are not in the eyes), a motion sensor, microphone/receiver for audio and a couple of bump sensors.

Aldebaran (the company that makes them) provides the robot with a default OS. The main problem is that it's not really efficient nor stable, so in general teams have to reimplement nearly everything. But to play around with it it's probably decently accessible - as long as you don't do anything really innovative. Aldebaran's website gives more info about it.