The race is on.
Deadline reports that Warner Bros. is picking up speed on its 2018 The Flash solo movie by hiring Phil Lord and Christopher Miller to develop a story for the movie. Lord and Miller are best known as the writer/directors behind The Lego Movie and the 21 Jump Street reboot (both suprise hits), and are reportedly being courted to direct the film as well.
After years of development, in October 2014 Warner Bros. formally announced The Flash movie with a planned release date of March 23, 2018. Relative acting newcomer Ezra Miller is cast to play the title role.
There's still no official word on if the film version of the Flash would debut before his 2018 solo flick, but with Batman V Superman: Dawn of Justice scheduled for 2016 and Justice League Part One scheduled for November 17, 2017, it seems very likely.