Tolkien would surely have been horrified at the idea of a great engine generating his world: "whereas it had once been green and fair, it was now filled with pits and forges." I imagine ents demolishing a wall of clustered machines.

But then Tolkien was a little bit uncomfortable with the world-creating industry embodied in his own works as well. The root of Melkor's evil in the Silmarillion is his desire to create his own world (when really all he can do is warp the existing one--changing elves into orcs). The conflict between Tolkien's utter devotion to his desire for unreal worlds and his willingness to look at the dark side of that desire makes for both interesting reading and interesting viewing. (It's a particularly relevant theme for geeks, I think.)

'"White!" [Saruman] sneered. "It serves as a beginning. White cloth may be dyed. The white page can be overwritten; and the white light can be broken."'