Probably no one will agree with me, but I'm not so sure I really agree with this statement after watching the first movie. Like iwy said, the Hobbit was very true to the book, and in all honesty, I think if PJ was going to do the same with the LOTR books he could have easily made at least 8 movies out of it instead of just 3. A lot was left out of those. I think PJ is giving a better treatment to the Hobbit than he gave to LOTR.
My problem with it is that I think it should have been two films, and then put all that stuff that didn't make the theatrical release into the Extended Editions like they did with LOTR. I'm slightly hesitant now, and gladly so. I'm just worrying about the flow being better with 2 films rather than 3. Granted as a completed piece, either way I think it will be great.
Really both this film and LOTR are one film, they're just too unbelievably long to make it in a single theatrical release. Think about it from LOTR. Did Fellowship or Two Towers have a climax? I don't think they did. Fellowship certainly didn't, and yeah Two Towers may have somewhat of a climax with Gandalf marching down the hill and the Last March of the Ents, but really this is just a subplot. The main plot is Frodo, Sam, and Gollum's journey, and that certainly didn't have a climax to it.
Plus the films on their own certainly don't follow the three act structure; Really Fellowship was the First Act (Breaking of the Fellowship is clearly the end of the First Act of the story as a whole), all of the Two Towers and most ROTK was the Second Act (with it ending at the Battle of Pelenor and Frodo and Sam entering Mordor), and then the 3rd Act goes from there.