This page lists changes that need to be made to the documentation, and sometimes contains some sections that are under construction.
The description of shadow map creation is a bit too shallow to be really useful. At least we should add some images, and an example RIB file demonstrating the use of shadowspot. Now that the autoshadows feature is finished, we should have that documented here as well.
The lists are probably not complete, and some options really require their own documentation page.
There's still some stuff which was added for 1.2 which is lacking proper documentation (see above). Autoshadows is the example that springs to mind, plus a few of the recent framebuffer features.
There are things being added to the 1.3 tree which are undocumented at this time. The recent work on DSM would need user-level documentation. The multi-threading stuff is less of an issue for end user documentation, it's more of an internal change, but it should still be reflected somehow in the summary of features.