Turn rumor caveats to full power. JoBlo has gathered together some possible spoilers and plenty of maybes from ye olde unnamed sources about the new Wonder Woman film. First, the facts: a Wonder Woman film is coming, starring Gal Gadot as the titular character, directed by Patty Jenkins. That's literally all that's been officially confirmed by Warner Bros so far. Also widely reported, including by Hollywood trades (but not officially announced/confirmed by WB) and generally accepted as fact, is that Chris Pine is playing Steve Trevor and Jason Fuchs is writing it. They're starting filming next month in the UK, and releasing the movie June 23, 2017.
The primary rumor that's been floating around for some time is that the film will be split between time-frames, with story taking place in both World War I and in the modern day. The villains are rumored to be Circe and Ares, both of whom have deep connections to Wonder Woman in the comics. In the current pages at DC Comics, for instance, Wonder Woman has actually taken on the role of the God of War, Ares, in the Greek pantheon. Circe, as a mythological sorceress, has been a foil of Diana's for decades, landing the role of her "opposite" in the online video game DC Universe Online. Neither of these is a giant leap, in other words.
The rumored plot, then, is that Diana and Steve are trying to stop the onset of World War III at the hands of the villains, while she relives the fights with Ares she had during the first World War. The main modern-day plot does come with an unexpected twist though, according to their rumors it will take place before the events of Batman V Superman: Dawn of Justice. Batman will also briefly cameo, if the rumors are correct, so when he and Diana "meet" in Dawn of Justice it may actually be that they already know each other.
Again, this is all rumor until official announcements hit, but it does all at least sound plausible. We should start hearing more about the film next month, and in the months that follow, as filming and production begins in earnest.