No surprises here really and it probably won't be hard to guess where DC is going after Superman vs. Batman in terms of solo films.
My guess is we're gonna see a solo Wonder Woman film since neither DC nor Marvel has capitalized on this glaring hole in their superhero lineup. While Black Widow does a good job at filling that role within these films she hasn't had a solo outing or one solely focused on her, she's sort of second fiddle to everything happening around her.
Batman seems like another strong candidate, give Affleck more time with the cowl and allow for the writers (perhaps Affleck himself?) to give new perspective on this take of the Caped Crusader.
Superman will no doubt get another solo film, especially in light of all the criticism about how the Man of Steel sequel isn't really about the Man of the Steel.
Green Lantern will no doubt get a reboot, this time focusing on John Stewart not only to distance itself from Ryan Reynolds outing as Hal Jordan but also to add a splash of color to the Justice League lineup.
The last one I see getting announced is a bit of a stretch but in light of the recent interview with Dwayne Johnson about what his role would be in the DC universe I'm guessing he's gonna play Black Atom in the Captain Marvel film.
The others I see being incorporated into the Justice League film in the same manner that Batman is being incorporated into the Superman vs. Batman film, they've just always been there. Flash will no doubt be recast from his TV counter-part, Aquaman showing up is a toss up, Martian Manhunter will be there, and I doubt we'll see Hawkgirl... yet. DC will want to give Wonder Woman as much space as possible to shine as a powerful female hero and once she's established Hawkgirl will be brought in to expand upon the female role models on offer.