It seems like all rumour circles are currently focussed on Canon. We have seen more rumours about the Canon EOS-1D X Mark II, and the expectation is that it will be shipped in the second quarter of 2016. Among the hot specifications is a dual Digic 7 processor, expected to take image processing to the next level.
Speculations are also rife about a dual slot for CFast cards, taking data transfer speed to an unprecedented level, with the addition of a whopping 20 frames per second continuous burst speed in live view. The other goodies speculated are 20MP CMOS sensor, 4K 60p videos, Touchscreen LCD, GPS and WiFi.