It has been revealed that New Line have registered the title: The Hobbit: Into The Fire.
This contradicts a number of official press releases that claim that the title of the third Hobbit film is: The Hobbit: There and Back Again. However, it is not uncommon for Studios including New Line to register multiple titles. In 2012 it was announced that The Hobbit would be extended from two films to three films and shortly thereafter, the company registered the titles: The Desolation of Smaug and The Battle of Five Armies.
The Hobbit: The Battle of Five Armies is a far grander title than There and Back Again as it suggests that the conclusion to the trilogy will be action packed. However, Into The Fire suggests that Smaug will have a significant and extended role in the film and that the events surrounding the character will be far more important than that of The Battle of Five Armies.
Regardless, I find There and Back Again to be a charming title that ties into the trilogy’s central themes and setting. It suggests that this is a tale written from the perspective of Bilbo Baggins while also taking inspiration from the novel.
Source: The Hobbit: Into The Fire