Joss Whedon says that its "very doubtful" that he will return to direct the two-part Avengers: Infinity War saga, which is slated for release in 2018 (Part 1) and 2019 (Part 2--see "'Black Panther,' 'Captain Marvel,' 'Inhumans' Movies" for the most recent schedule of upcoming Marvel movies).  The two Avengers: Infinity War films will be shot back-to-back in a process that Whedon thinks will take four years, and it sounds like the director, in spite of his love for the Marvel Universe, is anxious to get back to more personal projects.

Comic Book Movie reports that in an interview in the new Age of Ultron-themed issue of Empire Magazine (see "'Empire Magazine's' New 'Avengers: Age of Ultron' Photos"), Whedon explained why his directing the two-part Infinity War was unlikely: "I couldn't imagine doing this (directing another Avengers film) again.  It's enormously hard, and it would be, by then, a good five years since I created anything that was completely my own.  So it's very doubtful that I would take on the two-part Infinity War movie that would eat up the next four years of my life.  I obviously still want to be a part of the Marvel Universe--I love these guys--but it ain't easy.  This year has been more like running three shows than any year of my life. It is bonkers."