Nintendo has always been about better control of games. The NES controller was awesome for it's time, then the SNES controller improved upon it. Even though the Playstation was a little more powerful than the N64, the 64 had a superior controller, the analog controller. The Gamecube gave us a great wireless analog controller, and I don't even need to talk about the Wii's unique controller or the DS' touchscreen.
So yes, the successor will have a touchscreen like the DS, and maybe something else unique.
By the way, if anyone says that the Playstation had the analog controller, or the Xbox had the wireless, remember that they copied Nintendo.