NUblog: Dubliners, where the Joe-man laments the slow adoption of RDF: “What we need is for Web pages to categorize themselves, which categorizations could then be computer-read and -collected. It’s already possible, but it ain’t happening.”
He’s missing the point: there is no incentive for me to try to understand RDF or add it to my website. Langauges like RSS or XFML adresses the incentive problem by adding value to a website with additional incoming and outgoing links. People can add metadata to other people’s sites (a core concept that makes topicmaps (and XFML) really powerful): not everyone has to be a librarian.
RDF is dead as a popular metadata format. If it was gonna happen, it would have already. Forget about it.
Peter Van Dijck 
well, i don’t think folks will be hand-coding RDF anytime soon. but if your CMS auto-generated the stuff, like MovableType auto-generates RSS, and there are other systems taking advantage of it, then why wouldn’t it thrive?
Good point: people don’t *need* to know the innards of RDF. The fact remains: there is no incentive. What possible benefit is there for me to auto-insert RDF data in my website? None, really, just more bandwidth used.
The write-access problem remains as well: if in the future RDF becomes useful, I will need write access to all the legacy sites without RDF data to update them – an impossible proposition. XTM (topicmaps) solve that problem cleverly by separating the metadata from the content: you can add metadata to anything that has a URI (an HTML page, a Word doc, an image, …), no write-access needed. I think that is an obstacle RDF won’t be able to surmount.