Of course I've seen valve's original video, I am quite a fanboy of the steam controller so far :D
I am into the steam controller not for playing on a big TV (i don't have one and don't plan to buy it yet), but playing on PC in 1...2 meters away from the screen. Currently I play using x360...
I think a standard keyboard cannot be classified as a gaming device. Something like this or this might be. But anyway - keyboards were invented for typing, not gaming! Only then they were adopted to do gaming, but most comfortable and immerse gaming is only achieved with a good gaming...