So Curtis might be switching Medusa to Redland. This is very cool. OOo documents have a pile of metadata which is trivial to access (OOo documents are zip files, the file meta.xml contains Dublin Core and custom OOo metadata) and can be mangled into RDF easily. I'm following in Dave Beckett's footsteps by putting RDF directly into PNG and JPEG files. MP3 files normally contain rubbish, but with Sound Juicer the metadata is at least consistent, if a little lacking (MusicBrainz doesn't handle genre or year for a start).
If Medusa can slurp all of this metadata, and applications will actually set it, then we have a seriously cool metadata-driven desktop. Personally I can't wait.