According to a forum post on the LBP forums, a beta for LittleBigPlanet 2 is set to drop soon. While they haven't announced any recruitment methods for the beta, they have confirmed that anyone in the beta group will automatically be qualified to participate in the beta.
The beta will most likely consist of the new platform creator (level editor) where your imagination can run wild and you can become your own game-creator[...]
Continue reading: LittleBigPlanet 2 Beta Coming Soon...