We're told that a new 50mm lens from Canon will be announced alongside a “high end” mirrorless camera, which like means a Canon full frame mirrorless camera. We weren't told when we could expect such an announcement.
A few more people have told us that Canon has an EF mount mirrorless camera on the horizon and a new 50mm f/1.4 would fit nicely with such a release. As it would be smaller and lightweight and would suit both DSLRs and mirrorless cameras.
It was also mentioned that a new EF 50mm f/1.2L could be announced at the same time, as there are working prototypes out there.
A new Canon 50mm lens is definitely some kind of rumors unicorn and until we see one with our own eyes, all rumors on the topic will be rated [CR1]