Dec 21 2010
Nitendo announces the new Wii Remote Plus that features Wii MotionPlus technology. The physical look of the remote is similar to the original Wii remote.
Wii Remote Plus
To identify motion, the new remote uses an accelerometer. For other functions, the remote uses an infrared sensor, which traces the position of the sensor bar fitted to the TV.
The MotionPlus sensors have been integrated directly into the body of Wii Remote Plus. The remote measures 1.3x1.5x5.8 inches and weighs three ounces, same as the original Wii remote. The only difference between the original and the new Wii remote is the inclusion of more accurate sensors. Besides, both the remotes also share the same layout.
Source: http://www.nintendo.com/