Warner Bros has an excellent working relationship with Chris Nolan. Nolan has stated quite clearly that he has no wish to continue this universe. Warner Bros would be rocking the boat with this relationship if they even considered doing something without first seeking Nolan or Goyer's blessing first.
And that isn't really outside the realm of possibility. A lot can depend on how much Warner thinks they can make by continuing in this continuity and what they might have in mind.
Candidly I haven't much interest in seeing a Justice League film, but that doesn't mean I wouldn't enjoy it if it came to be and done well. I had no burning interest in an Avengers movie and yet I still enjoyed it. But Warner seems intent on doing a JL film first and then maybe branch off into separate character films...with the possible exception of Man Of Steel.
And I'm ambivalent about MoS---I want to see a good Superman film even though I'm not keen of some aspects of what I'm hearing about MoS. I had hoped Green Lantern
would have been better and I'd have liked to see a good Wonder Woman feature, but doesn't look like I'll see either before the JL project comes to light first.
Batman is my favourite of them all and I wouldn't mind seeing perhaps one more feature in the Nolanverse, be it a Batman Beyond type story or a Catwoman standalone. But I also wouldn't mind a relaunch exploring a more classic Batman similar in vein to an Alex Ross take on the character.