And thinking about other uses in education, besides offering guidance, I think books are going to be one of the places where AR best suits. Have a look to this video about an Augmented Book:
Although this technology is a fact, it exists, actually it exists for desktop computers with a webcam. The real power of AR comes together to mobile devices. There are some good applications of AR in mobile devices (mainly iPhones, Android and Windows Mobile), such as Layar.com:
Currently Layar is focused on geolocation-based AR, and not to signs in books. I want to find some spare time to research in some Open framework to support this integration with traditional books. Any idea?
I really think it would be more useful than current e-books (which are nothing really new, just text).