Microsoft R&D does some cool stuff. Kudos. I love where this is going—a laptop with this style tech and no trackpad at all would be very interesting, very minimal. At some level it seems like the kind of thing Apple would do—they've already removed the separate button from the trackpad, so removing the trackpad completely is almost a logical next step.

Looks like it might need to be a little higher res though, before it becomes productizable.