Here is a public link to the help index for the internal builds; it contains some information about the new features as well as extended information about current ones:
The help index is intentionally not compiled in a single file, as it tends to be quite large.
Well considering that the current help file is a work in progress that the final revision will be in the usual *.chm help file and if we ask nice possibly a *.pdf file.
Vlado, it seems that one image is not corresponding to its preview. Look at Raw GI Only preview
and now look at the bigger picture. This pic is same as Global illumination only pass.