I doubt Affleck will direct a Star Wars movie. I honestly don't get why all these studios are trying to get Affleck to direct these mega blockbuster movies like Justice League and Star Wars when it's blatantly obvious that he doesn't want to do these kind of movies.
I'm betting that Joss Whedon will end up directing one of the new films. He wants the job and would have jumped for the chance for Episode VII if it weren't for the Avengers 2.
This is definitely more likely. Whedon is Disney's golden boy right now.