The Nintendo Wii U is suffering from a bit of a drought of titles, with many “launch window” releases like Pikmin 3, Wii Fit U, The Wonderful 101, and Game & Wario being pushed back from their original expected release times. Nintendo president Satoru Iwata apologized for this circumstance, as it was something that he'd hoped the company would avoid with the Wii U.
"Nintendo takes seriously its responsibility to offer a steady stream of new titles in the very early days of a new platform to establish a good lineup of software," Iwata said. "On the other hand, we also firmly believe we have to offer quality experiences when we release new titles. Based on our software development schedules at the end of last year, we concluded we should spend a little more time to satisfy our Nintendo standard of quality. I apologize to those supporting Wii U about the lack of titles in January and February."
After having said that, he laid out some unannounced titles from Nintendo, including a new Mario 3D and Mario Kart game for Wii U that will be playable at E3 2013. He also announced a Yarn Yoshi in the style of Kirby Epic Yarn, and said that a Wind Waker HD remake is in the works for Wii U, though an original Zelda installment on the system is a ways off.
Source: Nintendo Direct