Though the character doesn't actually appear in J.R.R Tolkein's The Hobbit, the appearance of the furry son of Drogo Baggins and Primula Brandybuck in the film sounds to be natural and organic enough to work. The purists will certainly have a cow though.

For more details on how it'll all supposedly go down, visit this site:
http://www.theonering.net/torwp/2011/01/07/41520-elijah-wood-will-be-in-the-hobbit/#more-41520