If Nintendo pulls this off correctly (allowing access to more buttons) , this  is the new way to play FPS's. No joke.  Using this control scheme , even your grandmother can play call of duty competently with little instructions.

Aiming is one of the biggest barriers in console gaming. If you think about it, aiming with an analog stick is pretty stupid , and in the future we will look back and laugh at such an award control scheme. IR aiming is better but has its barriers due to its dead zone/ screen dragging sensitivity  that can confuse new-comers.  But with gyroscope tracking in the wiiU controller,  aiming, rotating, leaning, ducking, heck even walking can be  done  naturally by the player. I can even see the army using something like this to train soldiers.

Imagine playing battlefield 3 in all its graphically glory; the feeling of holding a real gun in your hands, physically leaning from cover then holding  your body steady to pick of an enemy head-shot in the distance. The level of immersion this will add to every action in your typical fps is immense.

However, if  picture shown above is the final design for the new zapper, this particular setup would certainly have trouble being the primary option to play fps's. But a simple design where the user can access all  buttons  on the  wiimote is all that is needed.  With access to the d pad on the wiimote, advance  players can use it as a kind of "quick- turn" feature so they can still play  without having to rotate their entire bodies for 90+ degree turns . (Similar to what they did with Zelda OOT 3d with the bow aimming).

Again, if done correctly, then the biggest pros( the feeling of holding a real gun, virtual reality type of immersion, increased accuracy) will outweigh the only con( arms might get tired after lengthy play sessions). And you would prefer this method of play above all else.

EDIT:

For all those misunderstanding the control scheme.

For this idea u are not using the TV screen.  When the player, holding the controller infront of him, turn/rotate in real life, the first person camera would do the same on the WiiU screen. The reticule will remain in the center of the  WiiU screen also. So if the user wants to he can turn directly behind  and see whats behind him (like Zelda OOT 3d).  Even walk around  in real life( although it may not be practical  but  maybe for a fast strafe or somethin).

Indeed, I'm very interested in the off-screen uses of the gyro+screen and what it can bring into gameplay.

Look.. I'm getting old and fat.. I ain't running, turning, leaning and jumping around in the future just to play games... I can barely handle Just Dance 2... >_

Aiming is barrier?
*** hmm looks at my mouse
No I don't think so ;)

You'll do it and like it old man.

It may seem natural to you, but even tho mouse and keyboard is one of the best options to play fps its still got it barriers.  Using a  flat pad to control a reticule on another screen is still unnatural to some. The point I make is this the closest to real thing as you can possibly get at an affordable price

Isn't there still an analog stick on that gun behind a finger?

That's such a barrier >.>

Obviously you wouldn't be using the inferior analog stick to aim.

Like I said before; if we have  access to more buttons, advance/lazy  players wont have to do this at all times. But just use the gyro to make fine adjustments.

Looks a little flimsy to be honest. I cant do a roll and pop and shoot behind the couch with that.