Next year is a Photokina year and it would be very surprising if Canon doesn't have anything to announce for the show.
By the look of things, the 5DIII/6D split of the 5D-series was somewhat rushed - without a unified vision/strategy behind it.
So, my expectation is that Canon will be working to address that.
The most likely candidate for Photokina announcement is the 5DIV, IMO.
Probably with more megapixels (~30?) and modern amenities like WiFi and dual-pixel AF.
Canon needs this update in order to keep charging $3500 for the 5D series - while leaving room for better specs in the 6D successor, which should arrive sometime in 2015.
With a properly differentiated 5DIV, the 6DII won't need to be crippled, like the 6D is.
So, it should be a pretty compelling offering, without stepping on the 5DIV's toes.
In parallel, Canon will be definitely developing a high-resolution sensor that will be used for 4K video and high-resolution stills.
I can't tell which camera will have this sensor, though.
I don't see the 1DX/1DC getting updated at lest until 2016.
At the same time, I don't see Canon waiting that long without a high-resolution camera either.
So, not sure what they will do at the end.