Canon is rumored to replace the EOS 5D Mark III with two different bodies in the name of EOS 5D X and EOS 5D Xs. This also means that the replacement to the EOS 5D Mark III will not be called the EOS 5D Mark IV.
According to latest Canon Rumors, the Canon 5D Mark III successor may split into 2 branches. The Canon EOS 5D X model will be dedicated for sports and event photography (which is more straight forward successor to the Mark III), while the EOS 5D Xs for studiographers.
Canon 5DX is said to feature 28-megapixel full-frame image sensor and new DIGIC processor. However we don’t know both of the bodies will carry the same sensor or a different one.
Rumor : Canon 5D X and 5D Xs Coming
We already mentioned about the company testing two 5D Mark IV prototypes for 18MP and 24MP sensors. The former being the replacement for the all-rounder the EOS 5D Mark III which looks likely to use the bigger resolution sensor. If these sensor rumors were true and currently in testing than the studio-oriented model (EOS 5D Xs) should not use the 18MP.
So our guess; if this 18-megapixel sensor exists and will be a part of the two bodies for EOS 5D Mark III successor, then we can expect the EOS 5D X to come packed with this 18MP sensor, a video-oriented DSLR which can also record 4K videos. Considering the EOS 5D Xs a more studio-oriented model than it has to feature a bigger resolution sensor.
From Dpreview forum :
Just got off the phone.. Looks like Canon is to name the 5D Mark IV 5DX. 28 megapixels, Digic 6+-basically a souped up version of 6 just to name a few.
X branded bodies will be for event and sports photography. S will be for studio, landscape, etc