In a recent interview with Empire, Netflix CCO Ted Sarando acknowledged the strategy to launch a Daredevil TV series, followed by Jessica Jones, Luke Cage, and Iron Fist and then eventually the team-up "event series" The Defenders, was based on the success of the Marvel Cinematic Universe.
"It was really based on the theatrical model of The Avengers," Sarando revealed unsurprisingly. "Could you take another group of characters, The Defenders, and go about it the same way? Normally they do the big movie and then eventually they get to the group origin story. Having 13 hours to tell each of these stories, you can go right to the origin story and the action at the same time."
Daredevil is currently filming with Charlie Cox in the title role, and Sarando revealed (as was initially announced) Jessica Jones is likely the next to go into production. “Right now, the writers' rooms are open and they're looking at casting Jessica,” said Sarando. “Eventually the series will run very close together. You can then have a separate season where the characters will cross over."
Speaking of crossovers and responding to the question on every MCU fan’s mind, Sarando said of a potential Marvel big screen/Defenders crossover: "It has definitely been talked about."
Finally, according to IGN, in the print version of the interview the Netflix CCO said that the Daredevil series will reflect the dark, gritty nature (during certain eras) of the comic book series.
"The series will not be afraid to go darker than the film did," Sarando revealed. "What we love about this particular set of heroes is that they're a little more down to Earth. Costume wise and also in that these are gritty crime stories, more in the streets than in the clouds."
The darker tone comments match a hint made in July at Comic-Con International: San Diego by Marvel Executive Editorial Director for Digital Media Group and Marvel.com Ryan “Agent M” Penagos. At the convention, Penagos told fans that Frank Miller’s seminal (and decidedly dark, gritty) run on Daredevil “might be something to read in the next year or so if you want hints about something else we are doing.”
While he didn’t specify the TV show, the puzzle pieces seem to fit together.