With pretty sound logic, the Middle Earth fandom of The One Ring are arguing that the next Hobbit movie, hitherto known as There and Back Again, could be retitled Into the Fire.
In short, Warner Bros. have recently registered that name and while it's not clear why, it's doubtful that they'd be doing it 'just because' at this stage of the game.
A trailer for the film is no doubt getting pretty close now, and we'll see the subtitle there at the very latest. Personally, I'm expecting posters within days.
As to which title works best… I guess it depends what it needs to work at. I can imagine Into the Fire will sell better than There and Back Again. If there's one thing The Return of the King takes a drubbing for its the sense of sentiment in the final reel, and it might just be that Warner Bros. want to avoid anything in that vein, at least in the marketing.