I wonder if companies like Nyko will eventually produce their own Gamepad for Wii U.

There's a lot of improvement left to be done on the gamepad and the most obvious ones are capacitive touchscreen and a sleekier design. 

I would like to see something looking like this for example: 

It would be a nice alternative if you end up breaking your own pad and you have to go through the hassle of contacting nintendo to buy a new one. Or you just want an extra one for you, while the original bulky gamepad is for your kids.

It would definitely be nice if there were 3rd party tablet controllers. However, I'm not sure if it will be allowed.

We will likely see 3rd party GamePad's but they won't feature extras like capacitive touch screens as the console's API won't have the code to take advantage of it.

And I thought now about some other possibility:

A gaming tablet with embedded buttons - gamepad look alike then - running android, and that could also be used as a Wii U controller, able to emulate every aspect of it.

Capacitive just for the sake of being a more stiff surface with much more effortless touch input.

I get a little bit annoyed when I'm using my smartphone and then change to the 3DS for a playing session and I have to touch it with much more conviction that on my phone.

Another aspect that could be explored is the range. Could it be possible to upgrade it to 60 feet ? 24 feet seems good, but feels like it could be better with more.

I believe in a Wii U Gamepad Lite made by Nintendo with small improvements like a better battery life.

Still, the system wouldn't recognize it unless the peripheral maker included some kind of capacitive to resistive input converter so the Wii U still receives code it recognizes.  That might be expensive.

Can't update the range since it's a 2 way signal.  You'd have to boost range on both the GamePad and Wii U.  Maybe you could boost the sensitivity of the GamePad receiver but I'm not sure which protocol they are using to know if that's possible.

There probably will, considering that when the official ones are available they will be very expensive.

I remember people making hacks of their GBA, upgrading to a better screen that still worked wonders, with a better image quality. I though that touchscreens could be swaped as easily as that lol.

About the range, yes, that's a 2 way signal... Didn't think about that either. I'm such a flop.

@ Darktemplar

I could see it in the horizon, maybe after 1 year of the arrival of the PS4 and X720, to refresh the Wii U. 

A GBA screen is not an input device.  It doesn't matter what type of screen you use for something like that.  A GBA screen only displays the signal sent to it, it does not return a signal back to the system.   It's like using a differnt TV with your game console.  Same signal.

A touch screen is very different in that it must send electronic signals from the screen back to the system in a manner the system is designed to understand.   Resistive and capacitive screens have different signals.