I think the WiiMote and its successors are not "gimmicks". I would say they've not been fully explored or well implemented. Honestly, I was hoping for the Power Glove and some VR glasses from Nintendo. Not a mini-iPad for a controller 
I will wait and see.
Unlike your statement, I think the mini-screen controller is a good thing. For local multiplayer games it is something I have wished for many different times over the years.
The ability for player sitting next to each other to see a unique screen is a good thing for some games.
There are many games where you want to keep some limited information secret, such as the cards in your hand, or the exact choice of selected values in a guessing game. Imagine games like Clue where each person has their own set of cards and private notebook, or games like Battleship where you have your own private location of boats, or Scrabble where you have your own set of tiles.
I think this falls well within their historical audience. Nintendo's focus has always been that games are toys meant to be played with, fancy electronic versions of balls and dolls and blocks. They tend to prefer tactile interfaces, tend to prefer bright colors and playful sounds, tend to encompass the entire family rather than just a core gamer, tend to focus on local group play, and by sticking with that route have tended to succeed with the masses.
I'm curious to see how it works out, but I suspect it will do very well.