the 3DS game -- over on the Madden Blog, including a video showcasing a new surprise onside kick mechanic. You can check that out past the break.
The more significant feature is tuner sets, which were first introduced in the NHL series and brought over to football in NCAA Football 11 last year. It's a vehicle for updating specific aspects of a game, circumventing the need for a full title update and the red tape that comes along with it. The goal is to provide more frequent updates addressing individual problems rather than issuing massive updates periodically.