There's a nice post over at Stories from a Sound Guy that fills in some of the successes and failures involved in the creation and iteration of the physics sounds from TFU. Sound Designer Erik Forman did a great job of working with David to make sure the content sets were dialed in to the level of detail necessary to represent the system as it evolved over time. He does a great job outlining some of the technical challenges from a Sound Design perspective that he was able to overcome through iteration and top quality communication. Keep your ears peeled for some of his sounds in the TFU2 trailer!
Erik Forman - Stories from a Sound Guy: The Force Unleashed