EF 800mm f/5.6L IS II

Another mention
More mentions of a replacement to the longest lens in the Canon lineup. We’re told the new 800mm will be announced once the EF 200-400 f/4L IS 1.4x has begun shipping. There’s a possibility we’ll see at least a development announcement some time this fall. There was no mention of the EF 200 f/2L IS, a lens that was announced alongside the original 800mm only 5 short years ago. Beyond a new build type in materials, the lens will be a “nearly identical” optical formula, although improvements in vignetting and sharpness are probable.
Announcement timing could also depend on stock levels with retailers, not so much with Canon itself. I don’t imagine too many of these are made and warehoused.
I have had communication from a few other anonymous people that the next 800 would have a built-in teleconverter, which is not something I think will happen.