Dominic Purcell is going to be Heatwave in the Flash. He's going to show up in the 1oth episoide to team up with Captain Cold further setting up the rouges.
http://www.hollywoodreporter.com/live-feed/flash-dominic-purcell-heat-wave-729700Just wishful thinking but I hold there is some internal reconsideration about connecting the main TV series (Flash, Arrow, maybe constatine) with the films. Also I hope Shazam and Sandman aren't standalone and are in the DCCU as ell.
As for the dates
Mar. 25, 2016: Batman v Superman: Dawn of Justice
Aug. 5, 2016: Shazam
June 23, 2017: Justice League
Nov. 17, 2017: Sandman
March 23, 2018: Wonder Woman
July 27, 2018: Aquaman
April 5, 2019: Untitled DC Film
June 14, 2019: Untitled DC Film
April 3, 2020: Untitled DC Film
June 19, 2020: Untitled DC Film