Here is my takeon dropping the Game Pad, it could be done and it could work out good too, everyone talks about the 5 million users that would be offended and the handful of games that would be affected but here is the thing, if Nintendo dropped the Game Pad and cut say an extra hundred bucks off the cost of the console and sold it as an optional upgrade it would just be viewed as having packed in an accessory for a period of time and then removing it, they could patch any games that would be broken or just require those games to have the Game Pad anyways. Nintendo has done this before believe it or not, the NES came standard with the Zapper and launched with a game packed in that required the Zapper, after the machine took of they made the Zapper optional and sold separately and slowly support faded but sales of the console grew.
Suppose Nintendo drops the Game Pad, something that is a turn off to many, and sales triple over night, then software sales increase and support comes back, more games get made and everybody wins, the game pad remains an option for those who want it and they just re-package those games that use it as compatible with Game Pad and let the gamer decide which control scheme they prefer, they can do a motion controls only bundle that is akin to Wii Mini that they target to the casuals and pack it in with a new Wii Sports and an updated Wii Fit or something and get some of that market back, then they have a cheaper entry level system for those who want the machine but don't want the high price tag. Can they completely bury the Game Pad and forget about it, no but they can remove it as an mandatory bundle pretty easily and the games that require it can be labeled as such and the gamer who cares enough for that feature or game will buy it, like the people who buy the Balance Board or the Microphones or Kinect or PS Move, etc.