Per discussion at Audio WG f2f 2013-03-26
The section on up-mixing and down-mixing should be moved to the audio node definition, thus collating information on handling channel allocations into one place.
Consolidated section 8 into section 9 in a more organized way.
For now, leaving this all in section 9 as a normative section since it's rather long and would interrupt the flow of the AudioNode section if it were moved there.
Consolidation looks good. Closing.