The website for Christopher Nolan's third Batman film just went live, and it contains clues that lead to this picture. Which appears to be Tom Hardy as Bane.
The Dark Knight Rises website actually contains a sound file of some chanting, which turns out to reveal a link to a Twitter account, TheFireRises, when you run it through a sound analysis program. That account, in turn, just tweeted this photo.
Hardy is almost unrecognizable as Bane. He's a lot more imposing and scary-looking than we'd been expecting, actually. What do you think? [Thanks Tim!]