This is interesting - Canon filed a patent for a EF/EF-S adaptor designed for a full frame mirrorless camera. Recently Nikon also filed a patent for a full frame mirrorless lens. So yes, it seems that the Sony a7 will not be the only show in town soon.
Canon has also a new patent for EF-S 20mm f/2.8 STM lens for APS-C cameras.
Olympus patented a M.ZUIKO DIGITAL ED 500mm f/4 PRO IS MFT lens
