I wouldn't mind 1 or maybe 2 more mature franchises from Nintendo. But I don't think they are in desperate need for more. Zelda and Metroid despite not being rated M still attract a mature audience.
What?! I can't hear you over all this awsome! - Pyrrhon (Kid Icarus:Uprising)
Final Ultimate Legendary Earth Power Super Max Justice Future Miracle Dream Beautiful Galaxy Big Bang Little Bang Sunrise Starlight Infinite Fabulous Totally Final Wonderful Arrow...FIRE! - Wonder-Red (The Wonderful101)