I doubt I'll find the time, but I was day-dreaming about a potentially very cool graphics demo/video. Probably more for the developer community though.
Over the decades of computer graphics a number of different material/lighting improvements have occured. It'd be pretty sweet to have some sort of rolling demo that showed this progression. Something like a FPS with the camera walking down a series of corridors through various rooms....
Start off with some really old-school basic lighting (e.g. ambient only) and slowly progress through to the latest-n-greatest.
Stage 1: Fixed Function style
Ambient -> Ambient + Textures -> Ambient + Diffuse + Textures -> Ambient + Diffuse + Specular + Textures
Stage 2: Early Programmable style
Per-Pixel/Programmable Blinn-Phong (bump mapping) -> Shadow Volumes (Doom 3 style)
Stage 3: Advanced Shaders
Shadow Mapping -> Soft Shadowing -> Advanced Lighting Models (As per previous journal posts) -> High Dynamic Range and Tonemapping
Not sure if SH/PRT can be combined in there, as it sort of runs in parallel and doesn't really replace anything.