Marvel has put an Iron Fist movie back into development, according to Deadline Hollywood, with Rich Wilkes (who wrote the Vin Diesel flick XXX) assigned to write a script. 

Iron Fist was in development in the early years of the century, first as a Ray Park vehicle (see “Punisher Movie Gets Green Light”) and later just as a movie that was always three years out on Marvel’s list (see, for example, “Another Marvel Movie Update”).