We've already heard rumors that the replacement for Canon's ageing 50.6MP EOS 5DS DSLR is likely to be mirrorless, with those rumors suggesting the new camera will sport a sensor delivering more than 75MP.
Northlight has now been told that this number could in fact break 100MP, and if that turns out to be the case it would push the camera way beyond current mirrorless offerings, offering more than double the pixel count of the 42.2MP Sony Alpha A7R III and both of Nikon's offerings, the 45.7MP D850 and 45.7MP Z7.
Although it's not quite a fair comparison, it would also potentially see the new Canon EOS R mirrorless model competing with medium-format rivals like Fujifilm's forthcoming 100MP GFX 100S. Speaking of medium-format, Northlight's source also understands that there's now no longer any active development of a Canon medium-format product line.
What else do we know about Canon's potential high-resolution full-frame mirrorless camera? On top of the expected 100MP sensor, we could also see the arrival of in-body image stabilization (IBIS) according to CanonRumors.com. Evidently IBIS wasn't ready for the EOS R release, although prototypes with IBIS were being tested before launch. The absence of IBIS has been a bit of a black mark against the EOS R, so we'd expect Canon to include this tech in future camera releases.
We're unlikely to see a 100MP camera this year though, with a 2020 launch more likely – Canon will need to bolster its native RF lens offering beforehand to take full advantage of a 100MP sensor.