Apple introduces a mouse with more functionality than just one button, the Mighty Mouse. An early mac ad touted the benefits of one button, "Some mice have more than one button. The Macintosh has only one. So it's extremely difficult to push the wrong button." Now I'm afraid I'll push the wrong button.
This mouse looks cool. It all makes sense now. Apple didn't want to release just another two-button mouse with a scroll wheel. They've done quite a bit more. Update: Russell Beattie has a hands-on review of the Mighty Mouse.