Frankly, they were missing an ending, in my opinion. In the book, Saruman and Wormtongue had taken control of the Shire and the fellowship had one more minor battle to contend with, in which Merry and Pippin took the lead in fighting the evil men who Saruman had controlling Hobbits. Frodo, after seeing the abuse Saruman heaped on Wormtongue, tells the little man that he need not follow Saruman anymore, he was free. It is at this point that Wormtongue killed Saruman, by stabbing him in the back.
It would have been nice to see that they had to fight for the release of the Shire, which had also been enslaved by the war.