Siliconera's reporting on trademarks Nintendo has recently registered in Japan in relation to 3DS, one of which called "CrossPass" mode.
Several other related names like CrossPass Connection, CrossPass and CrossPass Network all sound like names suited to the tech's tag mode, which will allow players to exchange data with one another, even when on another game.
Nintendo also trademarked 3D Paddleball, 3D Challenge and 3D Hopper.
No idea what these could mean.
3DS is set for release by the end of March 2011.