Art.Lebedev Studio's Optimus Keyboard was originally slated for release on July 14th, 2005. It was a marvel to behold, with colour LCD screens on each keycap, allowing you to completely reconfigure the keyboard for different languages or different usage. The original page is still available.
After many, many delays while they tried to keep the price reasonable, according to the Optimus project blog, they've finally announced that it will be available for pre-order on December 12th. However, the keycaps are no longer colour and their idea of "reasonable" is ... wait for it ... $US1200 !!