Beyond XSD

Another interest I have, which I hope to explore and ferret out here is whats beyond schema?

Schema (XSD) and it's instance documents XML are a tremendous improvement over flat file and unstructured data - providing a means of both easily extending (growing) a domain data model as well as making the elements of the data very granularly defined. But there are many limitations as well. Technologies like RDF and OWL look to be the logic next step in further enhancing an insurance information taxonomy that would allow all the consumers of insurance data (both within an enterprise as well as external) to more effectively and more accurately be able to share data. That's the goal, as I see it anyway, to make insurance information transparent and available where ever, whenever its needed.

So my question is how to proceed? First I need to document some findings and discoveries.