Shaped like a household body scale with a white top and grey bottom, Wii Balance Board contains pressures sensors used to control the virtual movements. Also, the sensors are used to measure the user's center of mass and body mass index.

Wii Fit includes more than 40 types of training activities which fall into four fitness categories: Aerobic Exercise: 10-minute exercises that are designed to get the heart pumping, Muscle Conditioning: Controlled motions using arms, legs and other body parts, Yoga Poses: Classic poses that focus on balance and stretching, and Balance Games: Fun activities, such as ski jumping and heading soccer balls, which challenge the player’s overall body balance.

The players will be able to compare their results and progress on the new channel on the Wii menu. Two key measures are evaluated: Body Mass Index (BMI), a weight evaluation based on a ratio of weight to height and Wii Fitness Age, which is measured by factoring the user’s BMI reading, testing the user’s center of gravity and conducting quick balance tests.

Since the product has been released in Japan in December last year, Wii Fit already sold 1.5 million copies, and is expected to do very well on the U.S. market.

In fact, some analysts have forecasted that Wii Fit could be one of 2008’s blockbusters in the gaming industry.

Nintendo said that the consumers in the New York area who pre-order Wii Fit from the Nintendo World store in Rockefeller Plaza will receive a special bonus item. From April 18-20, the first 1,000 consumers who place a $5 deposit for Wii Fit will receive a limited edition Wii Fit T-shirt featuring the image and reproduced autograph of legendary Nintendo video game designer Shigeru Miyamoto.

Some Wii Fit trailers are available here and here.