This was not disclosed during the unveiling of the Nintendo 3DS. However, a Japanese business newspaper claims that the upcoming Nintendo 3DS gaming console may allow users to store multiple games on an onboard storage device in place of the conventional cartridges.
According to Kotaku, the move can be in an attempt to curb piracy since it will make the use of R4 cartridges to store multiple games unnecessary. However, that line of thought seems unlikely since this move will actually make it easy for pirated games to be stored more conveniently on an onboard storage.
The reason for the move may then be to make the game more portable. Cartridges are seen as a technology that can inconvenience portability and Nintendo’s move may be to fight just this. But this is rumor after all, and so have a pinch of salt ready.