Things are never simple when it comes to The Lord of the Rings. There was lawsuit after lawsuit, and now the second Hobbit film, that was supposed to be a bridge between The Hobbit and Fellowship of the Ring, could be at risk.
It seems there is an issue of copyright, which Guillermo Del Toro points out:
In the four books that are in the domain of the copyright, there are appendices and ideas and things that can be traced without risk. But I have to be careful not to overstep. We believe there is a way to create this film and make it interesting, but it’s too early.
So they can create a second film from the ideas and appendices that exist, however they have to be careful about wandering into other areas they don’t own the copyright to.
Del Toro also went on to say:
We believe there is a second movie, if there isn’t, there will not be. If we find it, we will shoot it, but by God, if we do not find it, we will not shoot it. I am anxious to shoot the book, and I’m willing and able to dedicate myself to shooting the [second film].
It seems at the moment nothing is certain and they still do not know whether to split The Hobbit into two movies, or contain it into one.
Guillermo Del Toro says on the TORn message boards that things will get started once he has finished his Hellboy 2 rounds and Peter Jackson has finished work on The Lovely Bones.