Here is another GSoC proposal. It is called Augmented Mirror. In short, it is to use a one-way mirror with 3D reconstruction/tracking to achieve augmented reality. The user sit in front of the mirror and interact with the contents which are projected from the back of the mirror (to the mirror surface).
The detailed proposal draft can be viewed at: http://docs.google.com/View?id=dhnrb7vw_208gpz2r7fr
Some in-progress photo/video: http://www.flickr.com/photos/andy-li/sets/72157622749828133/
It is actually my current final year project but I want to continue(potential PhD research topic) and open source it. A very basic prototype will be finished on May and I will use the summer to refactor the codes, let it become a toolkit of building other Augmented Mirror (especially the 3D reconstruction part). Also I want to try integrate multitouch in it (using Laser Light Plane Illumination or Rear Diffused Illumination).
Hope to hear what you think