Canon EF 800mm f/5.6L IS II USM lens:
This lens is rumored to be announced once the EF 200-400mm f/4L IS 1.4x lens is in stock and shipping. The announcement would be sometime in fall, 2013. Also rumor this new 800mm lens may has built-in teleconverter.
Canon EF 100-400mm f/4.5-5.6L IS II USM lens:
This lens would probably announced in late August, 2013. Some prototypes of the lens are currently in use in Asia. The main reason for this quick update is Nikon has released the new 80-400mm lens.