I think that the Wiis motion controls are in the ballpark and are quite satisfactoy but they fall short of what motion control should be. This is what I think the next gen motion controls should implement in the order that I think is important.

 1. Intuitive tactile controls need intuitive tactile feedback mechanisms. It helps ease of use greatly by using rumble to firstly verify that the controller picks up the movement and to indicate the strength of the action the (X)mote detects. You need this on both sides of the controller, not just one. It also has to be a better implementation than the Wiimote.

2. Better (X)mote position detection, with detection for the 2nd mote as well. Information such as where each mote is in space will help developers implement the controls better and more intuitively. It will enable developers to use gestures as well as motion to interface with the game.

3. Symetrical breakapart design. Do away with cords that tangle and interfere with movement and get two distinctive configurations instead of one for games. By making the design symetrical it makes it fit easier into your hands, and they will feel more balanced together. Furthermore it would be a good idea to make both the (X)motes shorter than the Wiimote so it pivots easier with wrist movement. Finally with a two handed configuration it gives an additional control configuration for games that require it. Games like Star wars - Force unleashed come to mind.

So what do you think? Does it make it better?

The next motion control scheme will come in the form of a pair of gloves, a pair of socks and glasses. You read it here first.

notice by your profile the only Wii game you state you own is Wii Sports - put a lot of research into this did you?

 I would argue that Wii Sports is (still is!) one of the best ways to understand how the Wii mote works or at least the motion control side of it (other games and mainly the channel menu help with the IR detection)

Actually I own Wii Sports, SMG, Zelda, Wii play, and im getting Mario Kart soon.Edit: And DBZ budukai and Excite truck.

 It was just a quick posting of my thoughts. How do you think they should improve upon the Wii design?

Actually one more thing, a more powerful console can take better advantage of the motion controls by increasing the types of games and thus gameplay options available to the developers.

Strategy, simulation, and larger game worlds with more sophisticated tracking using cameras.