Black Widow will return Scarlett Johansson to the title role, in a prequel that may explore her time working as a Russian agent for the KGB. It's unclear who Winstone will be playing but he's generally cast as physically imposing dudes in crime movies, so perhaps an authority figure of some kind? His resume has its share of studio blockbusters on it, as well, including 2008's Indiana Jones and the Kingdom of the Crystal Skull. I'd steer you towards his performance in John Hillcoat's brutal Aussie western The Proposition.
The rest of the cast consists of Florence Pugh, David Harbour, and Rachel Weisz, so there's amazing talent all around.
Behind the camera is Cate Shortland working from a script by Jac Shaeffer. Hopefully we'll learn more about Black Widow and the casting next month at Comic-Con.