WotC will soon be releasing the D&D Essentials line of products - which not only package the game in easy-to-manage ways, but also redesign existing classes and races. However, they're going out of their way to point out that the changes they are making to classes in the upcoming books are not replacements for the existing classes, merely additional options. They repeat it several times (they're beginning to get the hang of this dang intraweb!) presumably in anticipation of a flood of "now I have to shred my character and sell my hamster!" messageboard posts.