As other people mentioned this is obviously not something I would want in my notebook... but I can still appreciate the cool tech! I can also definitely see this kind of thing being used in things budget outdoor displays, specially if the UI is made to accommodate the lack of accuracy, and the camera is positioned on the side (since these displays are usually vertical).
Difficult to capture reflections across a large screen while also dealing with outdoor lighting, glare, and moisture. The touchscreen part isn't usually what makes outdoor signage expensive compared to IP65, temperature control, and a secure housing, all of which would still need to apply here.
This looks like a neat option for retrofitting, and I suspect it'd work for some non-screen glass applications too. A combined IR/visible light solution would be interesting too, since I suspect those are complimentary (IR touch has issues with radiant light, while this wouldn't; this would have issues with low/no light, while IR wouldn't).