When Kinect and other similar new technologies were introduced it changed the conception of what constitutes an interface. This is a fascinating topic and one that I am working on with my colleague Lars-Erik Janlert.
There is a new attempt to develop haptic feedback without have any physical contact with a device. Aireal is a new concept that sends small puffs of air towards a user in a way that leads to (some kind of) experiences of objects. The technology is developed by University of Illinois PhD student Rajinder Sodhi and Disney Reseach’s Ivan Poupyrev. [You can find a description and video here]
This new technology is another step in the development and change of what constitutes an interface and is an interesting example that I wished Lars-Erik Janlert and I had used in our newly submitted article labeled "Faceless Interaction - a conceptual examination of the notion of interface: past, present and future". In the article we develop a way of thinking about interfaces that makes it possible to understand historical versions of interfaces and to some extent predict interfaces that will come. I hope to be able to write more about this later (if the article is accepted).
PS. Today I read this article about Leap Motion which is a slightly different approach but on the same theme. You can see how it works here.
Here is another article by Janlert and me about interaction and interfaces:
Lars-Erik Janlert and Erik Stolterman. 2010. Complex interaction. ACM Trans. Comput.-Hum. Interact. 17, 2, Article 8 (May 2010), 32 pages. DOI=10.1145/1746259.1746262 http://doi.acm.org/10.1145/1746259.1746262