Copy-pasting from a duplicate thread:
I love my WiiU gamepad: surfing the web with it is so simple, typing with a d-pad is painful and the touch-screen speeds things up significantly; gyro-aiming is now my preferred way of aiming, aiming with a stick feels dated; and I like playing games with it while in bed. I also really love the art people make using the stylus. The only issue is the battery life but thankfully, the recharge cable is pretty long so I just hook it up to power when battery's low.
Hope it's backwards compatible with the NX.