Keys and Mice have not changed much 'recently' because they are mature products. They are amazingly excellent at what they are made to do, and evey attempt to 'innovate' these products has either flopped, or aimed at a nitche market because there is nothing to be done to make them truly 'better'.
There are other input methods, such as speech, kinect, leap motion, web cameras, touch-screens, EEG, and other great innovations which are all either working products now, or will be available very soon, but the OS does not properly support such input devices yet because the interface is made for keys/mice. MS is making strides at making the OS more open to these new input methods with win8... but we all know how Valve feels about that.