There isn't a lot coming out of the rumor mill currently. This generally means there is nothing significant coming in the near future, which isn't a surprise, as summer is generally a slow time of year for product launches.
The most highly anticipated product from Canon is the EOS 5D Mark IV and we're only getting small bits of information, below is list of the latest information we've heard about the camera, not much is new outside of the ship date.
- The EOS 5D Mark IV will come after the EOS-1D X Mark II announcement.
- Q1 of 2016 is the ship time Canon is aiming for.
- EOS 5D Mark IV will have 4K.
- New Speedlite metering system coming with the EOS-1D X Mark II & EOS 5D Mark IV.
- Sensors ranging from 18mp to 28mp are in testing for full frame cameras.
- EOS 5DS & EOS 5DS R a test for “two model viability”, a model split of the EOS 5D Mark IV still possible. (Though, we think unlikely)
- New DIGIC processor
The EOS C300 Mark II starts shipping in September, so I doubt we'll see a 4k DSLR launching at the same time.
There is also the Canon EXPO in September, which might give us some clues about the future of the DSLR.
There has been some suggestions of an NAB launch in April for the EOS 5D Mark IV, but I don't see that happened as I suspect a new Cinema EOS camera will come for that show. While it will have a lot of video oriented features, it's still considered stills camera.
Is an EOS 5D C possible?
Anything's possible, but we still put it as unlikely.