@goldfarb brought up the derivative issue.  Since NO-ONE is going to leave any nodes as original in their renders, than sharing .tgd's should not be a problem.
It would be derivative works.  yes or no?  I am not suggesting that people post NWDA's work at all ever.
Since we all have quite the collection of clip files and objects etc... If I throw them all together that is a Derivative work and is legal.  Correct?