It’s summer time and there isn’t of course a lot of rumors now. But so far we know this is going to happen the upcoming months:
Olympus:
In July they will announce the new E-M10III with 20MP sensor and 4K video
By end of the year they will announce new lenses
Panasonic:
They will announce a new entry level MFT camera in autumn
New 50-200mm Leica lens will be announced in autumn too
Sony:
The A7III is coming around November
135mm FE and 400mm FE by late Summer
Zeiss:
Zeiss will announce new FE lenses by end 2017
Samyang:
Samyang will announce a new FE prime lens by end 2017
Nikon:
Nothing new from Nikon. They are likely going to make a new start in 2018 with a large sensor mirrorless system camera
Canon:
One more EOS-M camera should be announced by end 2017
Fuji:
they will finally make a pause on the X camera front :) Some lenses will be released by end 2017 but we will probably have to wait til 2018 too see new X system cameras.