We're told that a new 50mm lens will appear in 2016, but we were not told whether it was the EF 50mm f/1.4 or EF 50mm f/1.2L that would be getting the replacement. 2015 saw the release of the EF 50mm f/1.8 STM (our favourite Canon product release of the year! Which was a good laugh for some), though most of us were expecting the EF 50mm f/1.4 to get replaced first.
We're told that an image stabilized 50mm lens is in testing, though no mention of aperture. We'd have a hard time believing Canon would release a stabilized lens faster than f/1.8 for the EF mount, even if it would be unique a product, and probably welcomed by many people. With IS comes added size and added cost, would you be ok with that?
We'd guess the mentioned IS version of a 50mm lens would be for the EF-M mount.
We'd like to see both the f/1.4 and f/1.2L 50mm lenses get a replacement sooner than later. Modern AF and build and perhaps a floating element in the L.