The Canon EOS 1DX Mark III has been talked about quite a bit since the initial development announcement in October 2019. Canon has been not-so-strangely quiet about the specs, although a few were announced during the development announcement that has since formed the basis of the pre-order listing at various online retailers.
Now, the full specs appear to have been leaked, if this report on Canon Rumors is accurate. It shows a 20.1-megapixel sensor (same as the Mark II) with 5.4K RAW internal video capabilities. The fact that these are leaking now, especially with rumours of a Nikon announcement at CES, we might hear more official word on this one in the next few days, too.