Wow, this really opens up a lot of possibilities.
Augmented Reality Aps like layar could be much more usable. Nowadays you look like a dork when pointing a mobile everywhere, somebody even got angre at me for taking pictures of him, when I actually was using layar.
Also, it can be a hazzle with the floating icons bumping around unsteadily when using the phonew camera. It will feel much more natural with the glasses just turning around your head.
A second big thing would be the possibility of using them for real 3D, since different images could be sent to the right and left eye, making it possible to cretate the depth for 3d.