If Man of Steel is a hit, I don't see any reason, if they use Henry Cavill's Superman and include a Batman and a Wonder Woman, why the audience would be intimated by a Justice League movie.
Do you mean intimidated
? If so, I agree.
People understand superpowers in broad strokes. Just showing the characters using their superpowers is all the introduction needed.
Also, notice how, of the two breakout characters in The Avengers,
Black Widow and Banner, one never had her own movie and the other was played by a new actor, never-before-seen in the part.