Daredevil himself has confirmed that 'The Defenders' will start production at the end of this year saying:
“What we do know is at the end of this year we’re going to be making The Defenders and, of course, Daredevil is very much a part of that foursome, I have no idea what the storyline is going to be for that show. I’m very excited to see how those world’s combine… and interested to see tonally how those shows become one.”
“In terms of wrapping up any storylines, maybe they’ll do some of that in The Defenders. Or maybe they won’t.”Marvel’s Defenders will be made up of Charlie Cox as Daredevil, Krysten Ritter as Jessica Jones, Mike Colter as Luke Cage, and Finn Jones as Iron Fist. It’s unclear at this time who the showrunner for the series will be or when it will premiere.
UPDATE: Marvel has just revealed that Daredevil showrunners Douglas Petrie and Marco Ramirez will return to head up The Defenders, with Drew Goddard also back on board as Executive Producer.