The Forza Motorsport series is Microsoft's answer to the sim racing series Gran Turismo. Developed by in-house developer Turn 10, the series has grown since its inception in 2005. Forza Motorsport 4 was originally demonstrated at E3 2010 as part of the hardcore titles for Microsoft's Kinect-focused press conference. At the press conference, a developer showed how you could physically walk around and examine each car from outside and inside the driver's seat. According to reports, the game will still feature these elements.
The trailer did not fully demonstrate what the game would have, merging both in-game and real-life footage together. One could predict that the game will feature more environmental aspects including weather conditions and muddy terrain to affect the controls and graphical effects within each realistic race.
While no specific date was given, the game is expected for release in the holiday season for 2011.