I have seen that the pioneer controller is almost generic. The only thing left seems to be the wheelDiam and wheelSep in the code.
To solve this, it can be several solutions:
- Add wheelDiameter and wheelSeparation as XML nodes of the controller
- Add leftWheel and rightWheel as XML nodes of the controller
- Some hack based on the joints (I don't know how but will avoid adding more XML nodes)

If Nate agrees with any of this, I can write the patch.
Also the name of the controller can be changed from pioneer_.... to differential_steering.

Also, this controller set the maximum torque to 10.1. This is something that other controllers may want to change?