The feast commemorates the most sublime moment in the history of time, the moment when the Second Divine Person of the most Holy Trinity assumed human nature in the womb of the Virgin Mary. Thus, it is a feast of our Lord, even as it is of Mary, although the liturgy centers wholly around the Mother of God. — The Church's Year of Grace, Pius Parsch
In recent years The Tolkien Society have provided information packs, bookmarks and posters for schools taking part in this event. They have also provided free posters for events held by libraries and the general public taking place near to the event, rather than on the 25th.
Typical events consist of readings and discussions, but some groups re-enact scenes from the Lord of the Rings books.
A Catholic Core The Lord of the Rings is also Catholic.
All of this should make viewing or reading The Lord of the Rings a more interesting and insightful experience for both Christians and Catholics.