According to The Wrap, Warner Bros and DC are putting a sequel to Man of Steel into 'active development' and the project is said to be a 'high-priority' for the studio.
A direct sequel to the rebooted Superman seemed like a no-brainer, it did solid business at the box office and some critics didn't entirely dislike it. Then some bright spark executive suggested Batman v Superman and Man of Steel 2 got put on the back burner. Following the wealth of negativity towards the treatment of Superman in Dawn of Justice (he had just 43 lines of dialogue), Warner Bros are keen to restore faith in the character.
It's worth noting that a Marvel style interconnected slate of movies wasn't the plan when Man of Steel was made. Having concluded his Dark Knight Trilogy, Christopher Nolan helped develop the story and tone, but for BvS all his subtle efforts were replaced with brashness and undiluted misery. While it's good news that a new solo Superman movie is potentially on the horizon, it does raise the issue of when Warner Bros are planning to release it.
The official DC slate currently has Wonder Woman arriving on June 2, 2017; Justice League is up next on November 17, 2017, with Aquaman and The Flash due summer 2018. There's also the small matter of Ben Affleck's solo Batman movie which has yet to be given a fixed release date. Warner Bros recently put October 5, 2018 and November 1, 2019 on the schedule for two as yet unknown DC movies. So, I think it's safe to assume that Batman and Man of Steel 2 will be occupying those slots.
The first trailer for Justice League recently dropped and contained more moments of levity than the three-hour Ultimate Cut of Batman v Superman. While that's not much of a feat, it does look like Warner Bros has listened to the fan backlash. I'm well aware that the DC roster of superheroes is darker than their Marvel counterparts, but a superhero movie shouldn't leave the audience feeling depressed.