Are revealed in an article by Polygon's Dave Tach from September 27th, 2013.
Over the course of 30 minutes of additional play, you'll determine your ability to use your brain while keeping an ice-cool head in high-pressure situations
Obviously the article contains slight spoilers. Full article here.
Note: The S.E. is currently a retailer only preorder bonus in the U.S. via Game Stop. Check your retailers for areas outside the U.S. for details on preordering and the availability of the S.E. (also called the steelbook / preorder version).