It was announced today in WB's CinemaCon presentation. A 2018 release is planned with a possible Hanna-Barbera cinematic universe spinning out of it.
Most intriguing of all is S.C.O.O.B., a Scooby-Doo reboot slated for 2018 directed by Tony Cervone. In an announcement video, S.C.O.O.B. was described as “our first shot at unlocking the whole Hanna-Barbera Universe,” implying that the long-term plan is for the Scooby-Doo reboot to lead into a whole series of linked franchises based on the cartoons of William Hanna and Joseph Barbera.