Not too long ago Rovio let out a hint that it would be forming a new feature that would bring location-based gaming into Angry Birds. Today more information has come about regarding this new feature where depending on your location, you will receive new content such as the Mighty Eagle.
This new platform, called Magic, will be added to all versions of the Angry Birds games so it won't be yet another game you have to install. Instead it will be pushed out in a future update to all Angry Birds games. Once it goes live, you will be able to unlock content like new levels and other things like the Mighty Eagle depending on where you are. It won't be for every location though, only fun places. This can definitely add a new level on entertainment to the whole series of games. This will all be done through their Magic platform which a mixture of NFC and GPS location-based system.
Just image, as an example, with the Beach Volleyball update to Angry Birds Seasons, that you happen to be at one of a few beaches that has unlockable content. So while you sit there and sun tan, you can play new content that is only accessible by being where you are. Rovio plans to be selective on what locations they designate as "Magic Places" to ensure that every venue that becomes a Magic Place is fun in some fashion and relates to the game as well.
Unfortunately, there is no exact release date just yet as to when this will push out to all Angry Birds games.