We've been told that Canon will announce at least 2 new “big white” lenses in 2018. This is a World Cup year and the event may be used for testing the final versions of the lenses.
The new patents seem to be geared towards further weight reduction of the big white lenses as well as a bunch of ways to reduce abberations.
None of of the following patents mention IS, but looking at the optical formula, you can see grouping of elements that points to IS being included.
Japan Patent Application 2017-215495
- 400mm f/2.8
- 300mm f/2.8
- 500mm f/4.0
Japan Patent Application 2017-215494
- 400mm f/2.8
- 500mm f/4.0
- 600mm f/4.0
- 800mm f/5.6
Japan Patent Application 2017-215493
- 300mm f/2.8
- 400mm f/2.8
- 500mm f/4.0
- 600mm f/4.0
- 800mm f/5.6
Japan Patent Application 2017-215492
- 300mm f/2.8
- 400mm f/2.8
- 500mm f/4.0
- 600mm f/4.0
- 800mm f/5.6
Japan Patent Application 2017-215491
- 400mm f/2.8
- 800mm f/5.6
- 200mm f/2.0
We had been told that it was possible Canon would return to the EF 200mm f/1.8L and add IS, however the latter patent seems to show it'll remain EF 200mm f/2L IS and receive a version 2.