 :If that is the most likely outcome, then it is best to keep it as it is.  Once the time comes for splitting, the part 2 stuff can be split into a new article, and this article can be simply moved to The Hobbit: An Unexpected Journey.  That way we only need to do copy attribution for the part 2 article, and the links will automatically redirect to The Hobbit: An Unexpected Journey without any broken double redirects.   