The latest patch for the Xbox 360 version of Fallout 3 fixes specular lighting problems, giving the game a significant graphics boost. Don't feel bad - I had to Google "specular reflection" too.
The new fix makes things appear shinier and highlights textures on environments so you can actually make out ridges on radroaches or the subtle bumps on irradiated flesh. This makes me happy because now I can pretend that the 360 version really is superior to the PS3 version.
Inside Digital Foundry reports that the new 360 patch slipped the fix in along with prep work for upcoming DLC. The patch hit Xbox Live March 2.
Fallout 360: New Patch Has 'Secret' Graphics Boost [Inside Digital Foundry]