Most people are unaware that even though you get more at the sides, you are in fact losing some at the top and bottom of the picture. In order to fit the movie to a specific size dimension some of the picture must be removed. If you don't believe me, the next time you watch a full screen vs. the widescreen format of the same movie take notice of the difference and loss at the top and bottom of the screen.
And here's another interesting fact for all you widescreen TV owners: Widescreen TV's deceive you into thinking you're getting a better pitcture, where as the TV only stretches the image making the image fatter than it normally is. Therefore the image is partially distorted.