A new Canon firmware update for Canon EOS 5D Mark III
is scheduled to be available April 30 according to the Canon USA product page
"A firmware update for EOS 5D Mark III is scheduled to be available on April 30, 2013. Please click here to learn more."
The firmware update will allow autofocusing at f/8 and uncompressed HDMI output support.
B&H carries the Canon 5D Mark III DSLR camera.