We've received a few more bits of information since yesterdays story about a Canon EF 200-600mm f/4.5-5.6 IS coming in 2016. We're told that the new lens will likely be announced in August 2016 and will cost around $1700 USD, which would put it just under the Sigma's 150-600mm f/5-6.3 OS Sport's $1799 price tag. This tells us it will definitely not be an L lens, but it should still have great optics and build quality, though weather-sealing would be unlikely at this price point from Canon.
We're also told that there will be an external dedicated teleconverter for the lens, which would likely be an additional cost. We weren't told if it was a 1.4x teleconverter or something else.
You can view the patent for the EF 200-600 f/4.5-5.6 IS optical formula here.
More to come…