You may find the OpenLink Entity Finder useful re. term location and lookups for the Word Annotation plugin. I am also sure their are other REST based services out there that will offer similar lookup services (which
is basically about ontology location and URI dereferncing). The plugin should have the ability to register such service providers.
I don't see why this tool can't evolve into a general purpose annotator with utility beyond a specific domain. For example, the
UMBEL bridge ontology does a great job of mapping Upper Ontologies to lower domain specific ontologies and vocabularies e.g. from OpenCyc down to FOAF, SIOC, MusicBrainz etc..