My view on/wish for the solo films is something that the majority of fans will agree to.
[yes, I know this is a JL thread, but I take the chance to write about solo films. All of them combind, as a concept, and not discussing just one certain superhero].
If Warner Bros find someone special director, who could do for The Flash what Nolan did for Batman, and catch the essence of the hero and place him in our world, but with an own distinct style. Wouldn't that be the best thing, even if it means that we won't get everything from the comic book style because it won't work for a live action aproach?
Then we will find a "Nolan guy" for Wonder Woman, a "Nolan guy" for Aquaman, a "Nolan guy" for Green Arrow (after the Arrow show has runned for a few seasons), a "Nolan guy" for Hawkman etc etc etc.
And how many different styles for "darker story" can be found on the palette? As of now, there is only one and it's Nolan's Batman. Everytime we get reports that the writers/the studio want to move ahead with a darker take on XXXXXX [...insert any superhero...], the people here just go nuts and compare it with latest Batman trilogy and THAT kind of dark story.
There are other kinds of dark, you know. If one of the characters would work very well in a "war movie" kind of style, then let so be. The same can be said if one character will be done the pure sci fi way.