According to recently rumors on CR, Canon is finally planning to announce a new 50mm prime lens in late 2017 to early 2018. This 50mm lens will be Canon EF 50mm f/1.4 Macro USM lens. This new lens will not have IS and will use the Micro USM motor we’re told. It will replace 25 year old EF 50mm f/1.4 USM lens.
According to rumors, announcement of this lens would be late into Q4. So it looks like this lens will be shipping in early 2018.