Once 1.0 beta is released things will be far more solid.
You have to understand that 1.0 is almost a 75% re-write (or re-structuring) of 0.9 so many things have changed. To an end user it seems the same but that’s because of much backwards compatibility work by Sam.
bbPress 1.0 is 150% the code size of 0.9
So when 1.0 goes beta, that would be a good time to start documentation.