based on the characters they acquired, I'm not sure its a monster deal. One is new, daredevil is OK and iron fist had one series of comics and a few guest appearances.
Not world beater characters by any means.
Daredevil is big. Both Iron Fist and Luke Cage have followers. Iron Fist had his own series in the 70's, shared a title with Luke Cage - Power Man and Iron Fist - for many years, and recently has been one of the New Avengers. Jessica Jones is newer and no doubt is included so they can have a female presence on the "team." She had a baby (Danielle (named after Danny Rand aka Iron Fist)) with Luke Cage and married him in New Avengers Annual #1.
I wonder if any other "Defenders" will make appearances in these other series? Founding members were basically Doctor Strange, The Hulk, and the Sub-Mariner. Over the years many others were members of the team including Iron Fist, Luke Cage, Daredevil, Clea (Doctor Strange's lover), Silver Surfer, Black Knight, Hawkeye, Son of Satan, Hank Pym (as Yellowjacket and more recently as Ant Man), etc. Later the team was re-assembled and modeled after the Avengers with these "founding" members: Angel, Beast, Gargoyle, Iceman, Moondragon, and Valkyrie.
Like the Avengers, over the years so many heroes have been associate members or recurring members so this series could easily rotate many fringe - or even well known - characters in and out of the mix at any time.
