The site has previously reported on a Green Lantern sequel that turned out to be false, so it's difficult to say exactly how seriously the news should be taken, but they also report that the studio has a wish list of five potential directors who have expressed interest, and that filming may begin by the end of 2013 for a projected 2015 release.
The studio has still not confirmed that the film is in development yet, although a number of other figures closely associated with DC Entertainment and Warner Brothers have done so, including Guillermo del Toro, who claims he was approached about Justice League at one point. Man of Steel and Watchmen filmmaker Zack Snyder has already talked about the movie as if it's a done deal, and persistent rumors that Gangster Squad writer Will Beall will be scripting the movie have never been denied.
A number of other filmmakers have denied involvement with the project, including The Dark Knight's Christopher Nolan, del Toro, Snyder and Argo's Ben Affleck. It's been widely reported that Affleck was offered the film and passed, but Affleck recently denied that version of events.
Brett Ratner is still rumored to be in competition for the film, as are Lana and Andy Wachowski. The identity of the other three candidates, assuming the rumors are true and there is a shortlist of five, are as-yet unknown.