"After development of Wii Sports Resort," co-director Takayuki Shimamura said in an Iwata Asks interview, "[co-director Yoshikazu] Yamashita-san and I were thinking about something new that would draw upon the knowhow for Wii MotionPlus. We tested gameplay that involved moving the Wii Zapper and having images from the Wii move in sync on a monitor in your hands. It was fairly well received..."
It was so well-received, in fact, that not only did it form the basis of the Wii U, it convinced Shigeru Miyamoto that the 3DS needed gyro sensors in it, "so even though the ship was headed out of the harbor, he called it back," said president Satoru Iwata.
A second controller prototype, visible after the break, looks more like the GamePad we know now, though it's built from two Wiimotes stuck to the sides of a touchscreen, wired to Nunchuk joysticks.