Canon 50mm EOS Lens on Sony NEX-7 with Autofocus
The new NEX-5R with a hybrid autofocus system (Phase Detection and Contrast Detection designed for speed and accuracy) should improve the autofocus speed shown in the video. Canon's EOS-M mirrorless compact camera uses the same hybrid autofocus system.
Our assumption was wrong - the Canon stepper motor (STM) lens is not necessary for the NEX to control the Canon autofocus drive. The Canon EOS to NEX adapter with AF drive shown can control a standard EOS lens. The Canon EOS-M requires an EOS M Mount adapter to drive the same lens.
If you have Canon EOS lenses and want a light, compact camera to use them on - this seems to be the best option so far.
Canon 50mm EOS Lens on Sony NEX Autofocus Drive from MX Camera
It's only a matter of time when these Canon EOS to NEX E-mount AF Drive adapters show up for sale online. Thanks MX Camera!
Here is the first video.