There is a lot of chatter currently about the potential of a new Canon EF 50mm lens.
The first bit of ‘evidence' people have let us know about is that the EF 50mm f/1.2L lens is missing from the Canon USA web site. This happens from time-to-time, most recently with the EF-S 17-55mm f/2.8 IS. The listings on the site were probably broken around the time of the EF 35mm f/1.4L II announcement.
Pricing drops on the EF 50mm f/1.2L is also cited as a potential sign.
As of today, we haven't heard anything recently about a new 50L or 50 f/1.4, although the latter could definitely use an update as it is 30+ years old, although you could also make an argument for the 50 f/1.2L, as the design is flawed and could really use a floating element to offset the focus shifting issues some photographers experience.
There is a lively discussion on the forum about this.