Even in a world where dictation is perfect, do you really want to be saying 'Colon, Dee' to enter in :D. Not to mention the implications on coding, or other places where the language we use is simply the middle man.
So, as Aaronem said, 'no'. Maybe one day if/when a device can just read your mind and immediately put what you are thinking on the screen, but until then, the keyboard isn't going anywhere.