Great news for Canon folks: Canon is still actively working on the new EF 24-70mm f/2.8L IS USM lens. The specific announcement date is still unknown, probably in late 2017 or 2018.
The new 24-70mm standard zoom lens with Image Stabilization feature will provide better performance than anything currently in the Canon lineup. Canon didn’t release this lens because the size is too big when with image stabilization feature, so Canon released a smaller EF 24-70mm f/2.8L II instead.
The previous rumor said this new EF 24-70mm f/2.8L IS lens will have the new BR element that on EF 35mm f/1.4L II USM Lens. This Canon EF 24-70mm f/2.8L IS will be more expensive than EF 24-70mm f/2.8L II USM ($200 off now), and it will not replace the current EF 24-70mm f/2.8L II USM.
Stay tuned for more info.