I think weve received the documentation before the code.
Ive searched extensively for gdipluseffects.h and the only mention of it is in the docs. Online, its only mentioned in the MSDN docs and your enquiry about it.
gdiplus.h does not refer to it nor does any of the other include files.
I did a text search through the entire platform sdk and couldnt find any of the referenced objects either, e.g. BrightnessContrast
so its not in any of the existing include files either.
Guess we just have to wait.
Ed