IGN chatted with Andy Serkis, who broke the news that you can expect a teaser trailer for The Hobbit: An Unexpected Journey (or possibly both films) before the end of the year.
Serkis, who is again doing the performance capture for Gollum and is a second unit director on the films, said “There will be a trailer fairly soon, actually. Around Christmas time, I believe.”
The most likely film it would be with is Sherlock Holmes: A Game of Shadows, since Warner Bros. is releasing that film, although The Adventures of Tintin also opens in North America right before Christmas. That film was produced by Peter Jackson and co-stars Serkis as Captain Haddock.