Batman vs. Superman: Everything we know so far

Like most superhero movies, it has been very, very difficult to find reliable information on Zack Snyder's upcoming sequel to Man of Steel. Since the film was confirmed at Comic-Con this summer, a few details have trickled out; you have undoubtedly heard that Batman will appear, and that he'll be played by Ben Affleck. But those are some of the only things Warner Bros. has confirmed about Batman vs. Superman. We don't who the villain will be, or which other superheroes might appear. We don't even technically know that the sequel will be titled Batman vs. Superman, though almost all early reports have used the title. What do we know about Batman vs. Superman, anyway? Here, a...