We’re told once again that Canon is actively working on an EF 24-70 f/2.8L IS lens. We’ve been told in the past that Canon was working on this during the time of the EF 24-70 f/2.8L II lens development.
One of the major reasons an IS version of the lens wasn’t released was the size the lens would be with image stabilization, so Canon released a smaller EF 24-70 f/2.8L II instead.
We’re told that two or three prototypes exist, but no final design has been decided on. The IS being worked on for the lens will provide better performance than anything currently in the Canon lineup, along with more optical upgrades, one would assume a BR element would be part of the development.
Do not expect this lens from Canon for 18-24 months at the earliest, as there’s no pressure to release it, even after Nikon recently announced a VR version of their 24-70 f/2.8.