Holy work-stoppage, Batman! The ongoing WGA strike now has Warner Bros.’ superhero bonanza Justice League of America in its crosshairs. A source tells Hollywood Insider that filmmakers would like another script rewrite and are now debating whether to begin shooting without one. The studio has a Jan. 15 deadline to either greenlight League for a spring production start — meaning a summer ’09 release — or push it into the post-strike ether. (Warner Bros. had no comment.) All seven superheroes have been cast — among them, Adam Brody, according to one report — but it remains to be seen whether they’ll get to fly this year.