http://www.rpgfan.com/news/2009/341.html

The official website's countdown may only end next week, but courtesy of JUMP magazine, we already know that the game being teased by Square Enix is called Hikari no 4 Senshi (Four Warriors of Light): Final Fantasy Gaiden. The newest addition to the company's ever growing library of DS titles apparently will offer a classic take on everybody's favorite game genre complete with a "save the princess" story and traditional turn-based battle system. Equipment changes will be reflected by the respective character models.
Hikari no 4 Senshi: Final Fantasy Gaiden for DS will be available in Japan sometime this fall.