"2013 is the Year of Luigi."
And to emphasize Mr. Iwata's statement, Nintendo revealed today several Luigi-centric games. One of the games included New Super Luigi U, a new 2D platformer in the same vein as New Super Mario Bros. U. Unlike its predecessor, New Super Luigi U will not feature the chubbier brother at all. For that reason, Nintendo is refraining from having the word "Bros." in the title.
New Super Luigi U will be released as a downloadable title via the Nintendo eShop in 2013.