Keiji Inafune has announced, during a Team Ninja press conference, that Yaiba: Ninja Gaiden Z is a reality. Not much was said about the game, other than it features a ninja named Yaiba who will be chasing down the original Ninja Gaiden hero, Ryu Hayabusa.
The hopes of Team Ninja are that Yaiba becomes a spin off series of Ninja Gaiden. They did not announce which system it will eb released on, or a release date, however one would assume that Wii U will find a place for it alongside Ninja Gaiden 3. The only clue was the word “consoles” in their announcement, so it does not appear to be a Nintendo exclusive unless it will be developed for 3DS and Wii U.