I think these touchpads will best be utilized in virtual reality. The vive controllers are really smartly designed for utility. People seem to have all sorts of terrible preconceived notions about motion controls, when really, its all just 3d mice.
I like valve's solution because it follows a lot of good ui design philosophy, namely that you break down a selection into stages. What I mean is that, assuming a game like say shenmue in vr using the vive controllers. Your arms and wrists are used to move your in-game hands to areas that you want to interact with. Say you close the door behind you and want to lock the door. You would move your hand to a spot close to the door, at which point you would check the position of the controller in 3d space to see if it collides with a boundary box around the door and lock. Once it collides, your touchpads become context sensitive inputs, like zelda. Imagine locking the door - you move your hand near the door, and once it is close enough you get a prompt to use the touch pad. Imagine, to lock the door, you touched your thumb at the top of the touch pad, the rotated your thumb around the edge of the circular pad to actually lock the door, like you were turning a deadbolt lock irl.
Or imagine flipping a light switch - move your hand close to the light switch, then flick your thumb up from the bottom of the touchpad to the top.
Those touchpads give you the ability to discern a very fine point in 3d space with your fingers. These are just off the top of my head ideas, but I know some devs like the eden river people are already trying stuff like this with the vive.
