1. because the basic LOD generation process seemed to be more or less solved, and
2. because I started working on a mod for Oblivion.
Generating heightmaps from RAW files is a different beast entirely, and shouldn't affect the LOD generation process. I can't really tell you anything about that, though, because I don't have access to software that handles the kind of RAW files required by the Geck. (I use the Gimp.)
I'm toying around with a new FO3 mod idea, so I might be around the forums if you have any questions about LOD. Can't guarantee I'll know the answer, of course.