All major textures in the game were increased to 400%+ of their original pixels, sharpened, and had some detail added. Then new normal maps were generated to take advantage of the greater detail, which results in a significant improvement over the original graphics. This enjoys 0% compression files, which helps offset the fact that larger files requires more system resources.
This is a slide show of my Landscape ReTexture mod 2.0 for FNV. The song is "The Sodom and Gomorrah Show" by the Pet Shop Boys. It was downgraded significantly, so if you like it pick up a copy at your favorite online store (and hear it properly).