Satoru Iwata announced today during his keynote address at GDC, that a Super Mario 3DS title is in development for their recently released handheld, the Nintendo 3DS. The new Mario game is in development by the team that worked on Super Mario Galaxy, EAD Tokyo. The logo for the game features a small tail on the end of the Mario font, so the return of the Tanooki suit is not out of the question.
Iwata closed his comments on the new Mario game, telling that the next we would see of the new title would be at E3 2011. So for now, the screenshot above is the only information we have to go on about the upcoming 3DS title.