In an interview with French site GameBlog, Nintendo designer Shigeru Miyamoto expressed a desire to release the new Mario this year.
Super Mario Bros for 3DS was revealed by company president Satoru Iwata during this year's GDC as a new platformer that hopes to solve "how to jump and hit a block floating in a 3D space". Not much else is known except that a "tail" in the project's logo is significant, plus the Super Mario Galaxy team is caring for the new born 3DS game.
When asked about Super Mario 3D, Miyamoto replied "I promise to do everything to bring you a New Mario game this year", with a cheeky glint in his eye.