I have used the ultrahaptics boards before. They are pretty cool but they still don’t have the resolution I would want.
That said, you are right. The implications of haptics in mid-air interactions could be huge if we manage to create a cohesive and common-sense feedback language that will inform the visual feedback that the “hologram” already gives.
The other big use I see is no-look interactions like the lady driving the car in the video. These modern cars that go for sleek flat surfaces and get rid of tactile feedback will definitely need something like this.