I don't recall seeing this date anywhere before. It now shows in the link to the 5D3 firmware on CanonUSA's website that the firmware will be released on April 30th. It use to show late April like we have been hearing since back in October.
Look at the advertisement/link on the right side of this page:
http://www.usa.canon.com/cusa/consumer/products/cameras/slr_cameras/eos_5d_mark_iii
Bob
Look at the advertisement/link on the right side of this page:
http://www.usa.canon.com/cusa/consumer/products/cameras/slr_cameras/eos_5d_mark_iii
Bob