This one is cheating -- the Courier never made it out to the CES exhibition halls. The tablet concept from Microsoft took a different approach. It opened like a book with screens on both the left and right. You could use one screen to display information while jotting notes on another. You could flick content from side to side. It looked like a tablet designed to aid productivity.
But apparently, Microsoft never intended to acknowledge this concept. It was an internal project that leaked to the public. Journalists jumped on the information -- the concept video showed a tablet running a new operating system. It didn't look like Windows Mobile. Could it be a hint of where the company was headed?
In 2010, Microsoft officially canceled the Courier project. But some of the design elements seemed to reappear in the Windows Phone operating system and later in the Metro design for Windows 8. Could we one day see the return of the Courier? Hope springs eternal!