You're right Gok, Legolas was never in the hobbit. And for that matter, neither was Galadriel, yet Cate Blanchett is in the hobbit as well. When you are stretching what is essentially a kids book out to 3 movies, I suppose you have to create a few extra characters and plot lines to fill the space.

The other reason for them that I just thought of might be to expand along the Necromancer plot line from the book. The only reference in the book was Gandalf telling the others about events with him and saying to stay the hell away and at the end of the book to say he was driven out of the wood. Peter Jackson may expand upon this idea and turn it into a major story line in the movies.

We'll see…