High Quality Remote Controller Motion Plus Accessory for Nintendo Wii

In a nutshell, Wii MotionPlus is a new accessory for the Wii Remote that plugs into its expansion port, which promises to provide true 1:1 motion and position information to the console.

Nintendo's official press release can be found below:

"Nintendo's upcoming Wii MotionPlus accessory for the revolutionary Wii Remote controller again redefines game control, by more quickly and accurately reflecting motions in a 3-D space. The Wii MotionPlus accessory attaches to the end of the Wii Remote and, combined with the accelerometer and the sensor bar, allows for more comprehensive tracking of a player's arm position and orientation, providing players with an unmatched level of precision and immersion. Every slight movement players make with their wrist or arm is rendered identically in real time on the screen, providing a true 1:1 response in their game play. The Wii MotionPlus accessory reconfirms Nintendo's commitment to making games intuitive and accessible for everyone. Nintendo will reveal more details about the Wii MotionPlus accessory and other topics Tuesday morning at its E3 media briefing."

Well you see, when a peripheral of this magnitude gets added, it really takes most of the energy from the users hand, extrapolating the heat and turning it into a viable energy source. So to answer your question, yes - however it gets recharged using the energy from your hand.

Virtua Tennis 2009 - SEGA
The world's top tennis stars are hitting the courts again this May in SEGA's Virtua Tennis 2009 for Wii. Now every swing is more precise and the action is more intense, thanks to the Wii MotionPlus. Other updates include brand new courts, a new roll call of tennis stars to compete against and even more court mini-games.

Tiger Woods PGA TOUR 10 - EA Sports
From EA Sports, experience a near perfect 1:1 swing with the Tiger Woods PGA TOUR 10 bundle, featuring Wii MotionPlus. Elevate your game with an enhanced, true-to-life golf swing that features precise draw-fade capabilities and authentic sports motion.

Grand Slam Tennis - EA Sports
Can't get enough tennis? Excitement is in full swing with Grand Slam Tennis from EA Sports. Compatibility with the Wii MotionPlus accessory makes it possible to spin your racket and control your in-game player with superior responsiveness and control.

Wii Sports Resort - Nintendo
Just as with Wii Sports, people will love competing against friends and family. As the competition heats up, Wii Sports Resort is as much fun to watch as it is to play. First-time players will find it easy to pick up a Wii Remote and jump into the action. A wide range of activities will keep players coming back for one more round. Some sample activities include Sword Play, Power Cruising (racing a personal watercraft ) and Disc Dog, which involves accurately tossing a disc to a cute, Mii-like dog.