Director Zack Snyder's 2016 film Batman V Superman: Dawn of Justice takes place after the events of the director's 2013 Superman reboot Man of Steel: the first brick in the wall that is the DC Extended Universe. However, Batman V Superman is only really a sequel to Man of Steel in the way that The Avengers (2012) is a sequel to Captain America: The First Avenger. For that reason, many a DCEU fan has been waiting for a more traditional (read: direct) sequel to Man of Steel to start making its way down the pipeline.
Warner Bros. Pictures, when it officially announced the DCEU film release slate through to 2020, also confirmed that both Superman and Batman solo movies would be part of the DCEU package during that time period. However, even with Ben Affleck now confirmed to be co-writing and directing the DCEU Batman movie (in addition to reprising his role as the Caped Crusader), there's been no real progress to report about Man of Steel 2 over the past couple years (rumors and speculation aside).
The Wrap (via its newest addition, Umberto "El Mayimbe" Gonzalez) is now reporting that Man of Steel 2 is in "active development" and a "top priority" for the studio. Furthermore, the report emphasizes that getting Henry Cavill's version of Superman "right for audiences" is the biggest concern for WB/DC at the moment.
Man of Steel 2 has thus joined the DCEU release date "waiting list" that also includes The Flash and the Batman solo movie, in addition to (possibly) either a Suicide Squad sequel or the Harley Quinn-led spinoff. Right now, though, Man of Steel 2 is the only one of those listed DCEU projects that doesn't have either its director formally in place and/or a screenplay being actively written - as far as we know. There's a lot in flux in that respect though (see Affleck having made it clear that he intends to get the Batman script "right" before he agrees to a release date), so best to not jump to conclusions about how far or close the Man of Steel sequel truly is at this stage.
One assumption that can be made at this stage, however, is that either Snyder won't be calling the shots on Man of Steel 2 or the project won't be happening for a while. The filmmaker is currently in the midst of production on Justice League and may well move onto directing Justice League 2 immediately thereafter for a 2019 release. In other words, it appears unlikely that he will be able to commit to another Superman solo movie in keeping with WB/DC's presumed timetable.
Another element that will affect the Man of Steel sequel is the fact that newly-appointed DC Entertainment President Geoff Johns will play an active role in developing the film, as either a producer and/or even as a co-writer (like what's he doing on the Batman and Wonder Woman DCEU movies). As such, those who haven't been so crazy about the version of Superman presented in Snyder's DCEU movies thus far might even find the iteration in Man of Steel 2 (a - literally - reborn Kal-El, following the events of Batman V Superman and Justice League) more to their liking, too.
Suicide Squad is in theaters now. Wonder Woman opens on June 2, 2017; Justice League on November 17, 2017; Aquaman on July 27, 2018; an untitled DC Film on October 5, 2018; Shazam on April 5, 2019; Justice League 2 on June 14, 2019; an untitled DC film on November 1, 2019; Cyborg on April 3, 2020; and Green Lantern Corps on July 24, 2020. The Flash, the Batman solo movie and Man of Steel 2 are currently without release dates.
Source: The Wrap