Canon Rumors has a picture of the Canon Eos 1DX II video frame rate options. In this image the highest frame rate listed is 59.94P (in MJPG) at 4K.
The sensor is 20.2MP and has Dual Pixel CMOS AF which is a nice touch. CFast cards are required to work in 4K. Max ISO is 409600. Price is $6000.
Compared to the Nikon D5 this immediately appears likely the vastly superior option for 4K video, eve if the D5 gets an update to extend recording time from 3 to 30 minutes. C-Log is reported to be absent, unfortunately.
We look forward to seeing video clips from this camera.