HTML will continue to dominate the market of web publishing. People will continue to publish information in HTML because it’s the best markup language for displaying human-readable information in browsers. It’s the lowest common denominator for cross-platform information display.
If HTML is here to stay, then from the Semantic Web development point of view, we must figure out how to publish semantic data along side with HTML. In general, there are two approaches: (1) publish the semantic data of each and every HTML pages in separate documents, (2) embed the semantic description in the same HTML pages with RDFa.
If you ask which approach will likely attract web developers to share data, my answer is the latter approach (RDFa).
First, they would require less overhead in Web development. Adding few extra HTML attributes in the existing template pages is relatively easy. But, creating separate full-blown RDF documents would require completely different set of business logic and template pages. (…) Embedding semantic data in HTML gives web developers a sense of familiarity. People like to work with what they are familiar with, and many of them are reluctant to change.
In an early stage of the Semantic Web movement, some web developers may show signs of resistance to RDF document publishing. But, convincing them to use RDFa should be easy.