Canon is rumored to announce a new EF-S 24mm STM prime lens some time in this Summer. There are no detailed specs or the aperture info for the lens but it will definitely strengthen the EF-S line up, especially with the arrival of the EOS 7D Mark II.
Another rumor told is that Canon is working on a new USM motor technology, called C-USM (Compact Ultrasonic Motor). The new technology C-USM motor is said to appear first on a new 50mm lens which could also be announced later this year.
Canon EF-S 24mm STM Lens & USM Motor Coming in Summer