Deadline reports that as well as Shazam, Warner/DC is now also planning a standalone Black Adam movie.
Shazam (also known as Captain Marvel, although you can see why they’ve avoided that name) is the superhero alter-ego of a boy called Billy Batson. The hero has the powers of Solomon, Hercules, Atlas, Zeus, Achilles, and Mercury. While not particularly well known today outside comic book circles, he was the biggest selling character of the 1940s.
Black Adam meanwhile first appeared in 1945 as Teth-Adam of Kahndaq. He was originally a villain, but slowly transformed into an anti-hero who matches Shazam in strength, agility and fighting. He also knows magic. Due to his switch from bad to semi-good, it gives plenty of room for a movie with him at the centre, especially as DC showed with the commercial (if not criticial) success of Suicide Squad that you can have the baddies as the heroes.
No date has been announced for Black Adam, but Shazam is currently set for April 2019.