I did a research on this last year and from what I remember, J.R.R. Tolkien sold the television and radio rights to The Lord of the Rings and the Hobbit to pay off some debts in the 60s. Those rights passed trough the hands of a few companies and are currently owned by Saul Zentz/Tolkien Enterprises - not affiliated with Tolkien Estates headed by Christopher Tolkien-. Any media produced is based on this license. As such, Turbine isn't allowed to reference or use anything coming from Tolkien's other works - The Silmarilion, Unfinished Tales, etc-, which are still held by the Tolkien Estate.Delmar Wynn said:An interesting fact. There are 2 licenses for Lord of the Rings. There is the movie license which does not allow the reference to Tom Bombadil and then there is the book license which does. LOTRO is based off the book license and hence why we are able to meet Tom. I am sure there is someone out there that can explain to me why Tolkien Enterprise did I currently have no clue as to why.
My guess is that if something (e.g. Battle for Middle-Earth, I think) is based off the movie it uses the movie license and since Tom Bombadil wasn't referenced in the movie they can't use it, but if it uses the license directly from Tolkien Enterprises (e.g. LOTRO), then the company would have access to all the material in The Lord of the Rings and the Hobbit.