Pure speculation and just to reiterate, I do not expect an actual 5d IV 5D III replacement this year. If it is announced I expect it to be a development announcement. Maybe we will get a 2015 Christmas surprise but color me skeptical. I have no doubt it is coming. I expect it will have:
- Dual Pixel CMOS auto focus
- improved auto focus
- 4K video HDMI out.
- USB 3 Interface
- Improved SD Card read out (hopefully full speed UHS-II support)
- Improved video features Zebras, focus peeking etc.
- More FPS but still less than 1Dx
It will stay around the same MP but overall Image quality to improve. Of course Canon could be releasing the above specs as a Canon 6D II. Bump the Canon 5d IV to 39 mp with a AA filter. Then release a 50 mp 5Dc with out the AA filter.
Hence the rumors two high MP cameras coming with the 5d III replacement coming later. It will just be 5dc 50 mp with out AA and CMOS dual pixel auto focus. 5D IV around 39 mp with AA filter and CMOS dual pixel auto focus 5D (moved up market). The real 5d III replacement will just be called a 6D II (which moved up market).
Through in a Rebel using the current 6D sensor for an entry level full frame.
The sad thing is I think Canon could do all of the above if they felt like it. But it is unlikely. More likely there are two versions of the high MP camera in development one with AA and one with out. Canon has yet to pick which it will release. It would be unlike them to release both of them. But they have not made this decision yet. Then there is another camera in development that is targeted at the same market segment as the 5D III.
I do think we will find out soon what this high MP camera or cameras are.