Mark,
And everyone knows at least one way to publish HTML, don't they?
I disagree. Most people know how to enter text into a form, but they have no clue what HTML is all about, how it comes that one line of text is bigger while the other is smaller, how backlinks and permalinks are created and resolved, and so on.
The difference between publishing HTML and RDF (in whatever form) is exactly the difference between the Web and the Semantic Web: the former is "just" human-readable material, while the latter is machine- interpretable. Just as one needs to know the grammar and vocabulary of English in order to publish a proper textual description of goods, one needs at least basic understanding of the grammar and vocabularies of the Semantic Web to publish proper RDF data about these goods.
Even if blogs, CMS, and whatever other tools there are support the user in authoring RDFa with a nice GUI, it will be still up to the user to correctly select property URIs and to properly format literal values so that they can be used by a generic (!) RDF client.
Alternative: tools that do some sort of NLP / Entity Recognition / Information Extraction become so mature that they can be reliably deployed into mainstream blogs, CMS, wikis, ...
By the way, the same applies to the client side: in terms of applications we must get beyond the tabular rendering of RDF data. This is nice, but in the end it provides not much more value to an end user than a nicely formatted HTML page. The things that Google and Yahoo do are a good step in this direction.
Best, Bernahrd
