I don't think there's a movie trailer available, yet -- not an official one anyway. There are a few fan-made trailers on YouTube.
From IMDB:
"The script is written, but disagreements over distribution rights have repeatedly sent this project in and out of pre-production. Some of those involved have said the project is "dead", but Peter Jackson, the executive producer, continues to claim that this film will get made. In other words it's on hold."
http://www.imdb.com/title/tt0464037/faq#.2.1.5