The two movies that people suspected (or at the very least hoped) would be announced to be in the works were solo outings for Black Widow and Hulk. Both characters have shone brilliantly (let's forget about The Incredible Hulk for now) as part of bigger movies and appear to play a larger part than before in Age Of Ultron. All this suggested that Mark Ruffalo and Scarlett Johansson could be getting their names at the top of a masthead in the coming years, but clearly that's not the case; we will get a female-led Marvel flick, but it'll be Captain Marvel, rather than Black Widow. However, that's no reason to be disgruntled. Addressing the fan complaints, Kevin Feige has stated that both characters will continue to play big parts in the Avengers movies, leaving the door open for more prominent roles in other Phase 3 movies. In a way it makes sense to keep the fan favourites from being used up in inconsequential adventures due to the limits of contract restrictions - Mark Ruffalo has a six-picture deal, meaning he kinda needs to be used sparingly. Still, hopefully Phase 4 will bring us World War Hulk.
