Barring some kind of unforeseen issue, the Canon EOS-1D X Mark II will be shipping some time in April 2016. We mentioned this a few months ago and it looks like things haven't changed.
What may have changed is when the camera is announced, right now the latest information says a February/March announcement for the new camera. With Nikon having recently announced their flagship D5 which begins shipping in March of 2016, there's no reason to announce right away. However, announcing before the Nikon starts shipping is probably very likely.
The current planned price for the new EOS-1D X Mark II is $5999, but that could change slightly depending on currency strength at the time of the announcement, but it will be cheaper than the $6496 Nikon D5.
The only specification we have confirmed is that it will record 4K video, just like the D5.
More to come…