I am a gigantic fan of The Lord of the Rings and The Hobbit. I've read other works by Tolkien; I admit I wasn't quite as excited by them. Still, I admire the tremendous creative genius of Tolkien.
Other than knowing that he and C.S. Lewis were friends and friendly critics of each other's works, I know only a few other things about his life. He was apparently deeply influenced by witnessing the horrors of World War I as a soldier. He was an Oxford English professor (an achievement not to be taken lightly). He worked as a codebreaker in World War II, but I don't believe he and Alan Turing ever crossed paths -- however, it would have been interesting if he did. He invented languages as well as being acquainted with a lot of them. He got married once when young and had a long marriage.
Is this the stuff that movies are made of? Well, maybe.
Now, biopics have been made about a lot of people who one might not have thought had interesting enough lives to merit a movie about theirs. I imagine that they might try to merge his real life with his literary life (though I don't know how they'd do that). It's been done with other people, like American Splendor, about cartoonist Harvey Pekar. Another subject of a movie that might not be considered prime movie material was the recent The Man Who Knew Infinity, about mathematician Ramanujan.
According to the article, the movie (which hasn't even been written yet) will "... follow the English novelist's early years as a soldier returning from World War I, using his experiences from the battlefield to create one of the world's most cherished series."