RE: Equivalency

 
> The URIs resulting from each MAY be equivalent, but that's
> a separate question.

Yes, that is actually the heart of the matter.  WADL, and 
tools of a similar vein that employ URI Templates, needs a
set of validation rules that prevent illogical constructs
which can result from URI Templates that define equivalent
transformation functions.

 http://example.org/{a} 
 http://example.org/{b}
 http://example.org/{c}{d}
 ...etc...

are all effectively the same transformation.  I would just like
to see some wording to that effect in the URI Template spec.