Doesn't really matter. It will be months before you ever see one. What happened to the 200-400 that was all over the place at the Olympics? Pictures of it in the wild emerged a long, long time ago and nothing to be said.It hasn't been officially announced yet, big difference, in case that escaped you
It still doesn't matter, months pass even after they are announced. How long ago was the 500 and 600 II's announced? They have only recently started becoming available. Don't hold your breath with Canon, it will drive you crazy.
With so much of the development pipeline in the public view, its getting towards the stage where almost all of the current camera's you can actually buy from Canon are obsolete before you get them.
Come on Canon - shorten the announcement to delivery window.