Stunning!  If I ever get to choose a new floor this will be on the shortlist.  Just a little near a doorway would suffice, or as a design in the middle of a living area instead of a rug (underfloor heating of course).  The design allows for any pattern to be done when pouring or when the concrete has set.  The designers behind this is Transparent House, a 3D design and visualization studio in San Francisco.  

[via Dwell]