The Wii U’s big draw, the feature that makes it unique, is the GamePad, the controller with a large touch screen, which allows for control options that have never before been seen in console gaming. It also facilitates asymmetrical multiplayer, since only one person will typically be using the pad, while others will be saddled with Wiimotes or more traditional Pro Controllers. In this latter style of play, the player with the GamePad tends to get their own private screen, which provides unique information and a distinct perspective on the action, better accommodating their unique role.
If this sounds familiar, it’s because you were paying attention during the GameCube era, when the GBA uplink cable was released. Games such as Final Fantasy: Crystal Chronicles and The Legend of Zelda: Four Swords Adventure took advantage of the technology, the latter, in particular, providing each player their own unique screen when they left the main map to go indoors or underground. Shigeru Miyamoto also remembers the uplink cable, and the plethora of ideas he had for the pairing that were never realized. While many of the specifics of those ideas remain forgotten, Miyamoto recently expressed interest in seeing similar concepts brought to life on the Wii U, since the technology itself is ingrained in the base hardware.
Source: Nintendo Everything