It has a lot of biographical info. re: Tolkien, and it includes several interviews with cast,including Orlando Bloom,Sean Astin, Liv Tyler, Cate Blanchett, Ian MacKellan, Christopher Lee, Elijah Wood..............no Viggo, though:( as well as on-location footage and clips from the movie. The idea is to show "how the imaginary world of Middle-earth reflects our own." It describes Tolkien's inspiration for creating the story as well as how he went about creating the Elvish languages, etc. You get to see "Hobbiton" before it became Hobbiton, and they talk about how they had to do stuff like plant the vegetable gardens a year before shooting started, etc.I really enjoyed it.
Bummber about no Viggo interview, but I'm not surprised--I don't think he likes that sort of thing at all.