Seems that the only time you can really use 'better than Kinect' is when it's not about games. Like these real time projections using the Xbox camera to create the illusion of portals opening up in the wall.
It's been designed by creative software designer Roland Smeenk who posts all the real science here, although here's a quick summation:
By using one Kinect for head tracking and another Kinect for reconstructing a 3D view, the virtual window effect of a portal can be created in reality. By using both Kinects for 3D world reconstruction and head tracking a two way portal effect can be achieved.
I would pay actual money for this as an interactive installation ornament thing.