Nintendo has always been different and every since console the controller was set to innovate. Only one they didn't was the Gamecube controller because to them kidney beans is a set standard for 10 years lol. Second Screen of course started with Dreamcast then PSone then GCN and btw GCN they wanted motion controls and 3D. GCN like NES was originally not planned to have a successor but attachments to prolong it. Maybe why Wii was mostly a overclocked GCN. Wii original idea is the Wii U idea of not being tied to a TV (tho I remember some rumors about Shiggy and a projector or something) Wii U is announced and suddenly MS has Xbox glass and PSvita and PS4. Nintendo has to be the most copied company in gaming in both software and hardware. Even if the hardware is not selling amazing the fact other companies take the idea is innovation. History does not always reward the innovators but the ones who made the most noise. Steve Jobs is a prime example. Inventor of the computer mouse and I think the programming which OS is based on dies. No one noticed. Innovation isn't always sales. Like with Apple Sony has found a way to open up a GAP at a nudist colony. They do not innovate they copy(not saying this as an insult to Sony) MS buys like they did with the company Vcam(think was the name) that had a Kinect like Camera at CES 2008.
Personal standpoint I like the second screen. Not tied to a TV is really nice. Wii U eliminated (maybe was dead already) that sub market nyko had with those LCD screens for consoles. I like that I can play while watching because I always been one to do that.