As you may recall, Sony lost a lawsuit for millions of dollars to Immersion regarding Sony's use of vibration technology in its PlayStation 2 controllers. Sony subsequently announced that the PlayStation 3 would use motion sensing controllers instead of vibration controllers. Sony appears to be taking the matter seriously, and has at least one patent application pending on its motion sensing technology, United States Publication No. 2006/0267935, entitled "Remote input device." The application was filed May 27, 2005, and recently published on November 30, 2006. The application still has to be vetted by the United States Patent and Trademark Office before a patent will issue, but its a good sign of the direction that Sony is headed.

Link to USPTO copy of application.