I don't see why I would want to wave a wiimote at the controller I'm holding in my other hand. Neither do I understand how the controller is going to get I'm pointing at it (if it acts like a wiimote sensor, that'll mean there will be two...so how to separate the main screen from the wiiU-mote one?).
About the only feature I can think of where it wouldn't suck is when you put the wiiU-mote next to (or underneath) your television so you get kinda like two monitors. It's kinda hard to estimate the screen size (+distance from your television), but perhaps you could have a rail shooter where the mini-screen serves as your HUD, and pointing at it can select other weapons.