A touch screen, touch mouse, touch pad, but no touch keyboard? Seriously? Hey Microsoft (& others), I think you missed the forrest because of all of the trees.
It's simple really: why move my hands from the keyboard to further interact when I shouldn't have to? Let's place a small touch area in the keyboard right beneath the space bar, where it can be accessed by the user's thumbs as they type.
Any actual products born from this idea shall donate 50% of their profits to a reputable charity. You're welcome.