Natasha Romanoff/Black Widow is a character with a pretty rich (and dark) backstory in the world of Marvel comic books, though in the Marvel Cinematic Universe (where she's portrayed by Scarlett Johansson) that history has so far by and large only been alluded to, in such Marvel Studios movies as The Avengers and Captain America: The Winter Soldier. The ongoing mini-series Agent Carter has, if nothing else, laid the foundation for a deeper exploration of Natasha's past experiences at some point in the future.
It looks as though that backstory will be examined at least somewhat more closely in this year's Avengers: Age of Ultron, based on recent comments made by Johansson. Age of Ultron writer/director Joss Whedon has long maintained that Black Widow is a key player in the film's narrative, after all. Meanwhile, previews for the Avengers sequel have teased a major subplot from the movie involving Natasha's relationship with Bruce Banner/Hulk (Mark Ruffalo) - a thread that could easily give rise to more light being shed on Black Widow's background.
Age of Ultron will only have so much time to devote to any single character thread, as they'll be something of a secondary concern to the film's main conflict: Tony Stark (Robert Downey Jr.) having in part created the A.I. robot Ultron (James Spader), who then proceeds to attempt and wipe out humanity. Nonetheless, Johansson informed W Magazine [via CBM] that Age of Ultron will offer more insight on Natasha's past - something Johansson is familiar with, having read up about the character's history in the Marvel comic books.
“People were surprised that I wanted to play a comic book heroine. But I loved Iron Man, and I met with Marvel to see what was possible. I had done my research, and the Black Widow character resonated with me. She is dark and has faced death so many times that she has a deep perspective on the value of life. In the sequel, you learn more about the sadness in her past.”
Hawkeye/Clint Barton (Jeremy Renner) and Black Widow were the two Avengers in Whedon's first movie who hadn't previously starred in their own solo features (both appeared first in another superhero's film), though there's plenty of backstory material to drawn from for either character, when it comes to their comic book iterations. When it was mentioned that her description of Natasha indicated the character is as nuanced and multi-faceted as an other famous heroine, Johansson replied:
“I think of her that way. Black Widow is a superhero, but she’s also human. She’s small, but she’s strong. It’s hard not to admire her. She packs a big punch. We all try to fight the forces of evil. Like Black Widow, you have to keep trying. The challenge is always there.”
It's no secret that Whedon is an outspoken supporter of feminist geek culture, as reflected by his handling of Black Widow's character in the first Avengers; offering all the more reason to be interested in seeing him and Johansson explore deeper into Natasha's past in Age of Ultron. Marvel Studios doesn't seem to have any plans for a Black Widow solo movie, but her continuing to be a well-developed supporting character in the MCU will help to make up the difference.
Source: W Magazine