What Is Deus Ex: The Fall?

Something Deus Ex is being teased by Deus Ex: Human Revolution's developer Eidos Montreal. Spotted on their Twitter account was this cryptic message:

The name for Deus Ex: The Fall has been trademarked since March but this is the first time it's being discussed since. It's highly unlikely The Fall is connected to the Deus Ex movie in production because Eidos Montreal is the game development section. The idea of it being DLC could also be called into question. After all the game is about two years old; even though DLC can come out years after the initial game release (i.e. Scott Pilgrim).

Is it a new game? Maybe... no one knows what Deus Ex: The Fall is. What we do know is E3 will arrive in about a week, so the chances of The Fall being revealed is quite high.