VFXWorld is running a series of articles detailing the VFX work on STar Wars Episode III Revenge of the Sith. The first article is an overview of the work while the second article deals with the environments of the film.
The first article discusses having a layout dept., fluid and cloth sims and subsurface scattering use and the evolutionary aspect of the film compared to the first 2 prequels, by VFX Supervisor John Knoll and Animation Director Rob Coleman. The second article has an in depth discussion of the ILM matte department, the use of Zeno and commercial tools, plate photography for Kashyyyk and R&D for Mustafar, with comments from VFX Supervisor Roger Guyett, Matte Painting Supervisor Jonathan Harb and Matter Artist Yanick Dusseault. It also includes several great shot progression images of the matte paintings and ambient occlusion shots of 3D models.
You can read them here: