Japanese patent application 2010-282101 is for an optical communication between lens and camera body. The optical link will be added on the mount in addition to the regular electrical contacts (all Google translations):
“It is a camera accessory with which a camera body provided with the 1st communications department which communicates by contact, the 2nd communications department which communicates optically by non-contact.”
Even more interesting, this optical communication will be available as an accessory:
“It is a camera accessory with which the camera body provided with the 2nd communications department which communicates optically by non-contact, and the body side mount can be equipped.”
The patent application mentioned that this optical link will save space and will be more compact then conventional wiring.
The initial report from Japan indicated that this lens will be used in a mirrorless camera, but some of the drawing clearly show a DSLR type camera (D700 that is):
The above figure show the additional accessory 132 mounted on a DSLR. 136 are the electrical contacts (two or more) and 138 is the optical communication link:
