More bits about the EOS-1D X Mark II surface on the web. Canon Rumors writes:
We’re told that the sensor currently being tested in the EOS-1D X Mark II is 25mp. The sensor will be manufactured by Canon, so any third party manufacturing rumors can be quashed before they start.
This source is also confirming the likelihood of a new pair of DIGIC processors to handle the added resolution and maintain the frame rate of the current EOS-1D X.
Not very much, and I would take it with a big grain of salt.