Mayday
CAGiversary!
The collectors edition gives you exclusive in-game equipment, the steelbook and 3 dynamic themes. It's not much but it's worth it as the price is only a couple of £ more than the standard version.
http://www.simplygames.com/info/18234/MAG-Massive-Action-Game-Steelbook-Collectors-Edition-PS3
http://www.simplygames.com/info/18234/MAG-Massive-Action-Game-Steelbook-Collectors-Edition-PS3