The Next EOS-1?
We're told that their is a 44.7mp camera in heavy testing. However, the test cameras are eating batteries when shooting in 4K mode. Development is still continuing on the sensor, batteries and software.
I expect a development announcement for this camera sometime in late 2013 or early 2014.
Another two people have said Canon will announce a medium format solution for Photokina next September. The big push is towards MF, but probably won't see availability until well into 2015.
We're also told by a second person that such a medium format venture could be a unique arrangement with a current medium format manufacturer. Canon is serious about medium format and will continue to develop a strategy to become the market leader fairly quickly.
A grain of salt on these bits of information, as they're from unknown sources.