Although Man of Steel kicked off the DC Cinematic Universe, talk of a sequel wasn't all that forthcoming.
After all, we had Batman v Superman: Dawn of Justice and Suicide Squad, along with the Batman standalone movie and Justice League, but another Man of Steel movie seemed somewhat unlikely. For one, Man of Steel received good-to-middling reviews and the DC Cinematic Universe seemed to more concerned with everyone getting at least one film before moving on to sequels.
In any case, it looks the Man of Steel film is officially happening as a report by Newsweek confirms that Henry Cavill is actively developing the sequel under his production banner, Promethean.
The Man of Steel sequel comes on foot of the announcement that a Harley Quinn spinoff is in the works, with Margot Robbie acting as star and executive producer. In Warner Bros. / DC Comics' proposed slate, there's a slot in 2018 and 2019 that will likely be taken up by Ben Affleck's standalone Batman film and either the Harley Quinn film or the Man of Steel sequel.
George Miller was previously rumoured to be taking on the Man of Steel sequel, however that now appears to be unlikely whilst Zack Snyder will be coming off the back of Justice League and will likely need a breather once that's finished. What will make or break Man of Steel is, undoubtedly, its director.
Much was made of Man Of Steel's realistic approach to the mythos of Superman and there's a decent opportunity here to do something interesting, but it has to be handled right.