Hi Chris,
RDF is a useful technology, but unfortunately it is a tad
intimidating for many developers as it is not standard fare
outside the semantic web community. Beyond SMART Classic (what we
now call the 0.6.2 version that is going into support-only mode),
I am not aware of other APIs in the medical industry that employ
RDF, so I doubt that we will see much of it around. At this point
we are transitioning towards a new model that builds upon FHIR's
data models while applying the coding system constraints of SMART
and its app framework. "SMART on FHIR" takes the best of the
SMART and FHIR worlds and offers a unified platform for
integrating medical apps into existing and new systems.
Hope this helps,
Nikolai