God no! I've read some of the abomination novels that were the expanded Dune universe stuff and it was horrible compared to the originals. I don't want that to happen to LotR in a million years. Best bet is to film some stories from the Silmarillion.. the huge battles against Morgoth (who lets Sauron look like a noob) would make for epic eyecandy interwoven with Beren and Luthien's story. That's about it.. sometimes you just need to let things go. I don't know if Jackson has it in him to invest yet another decade into the LotR universe.