Almost nothing of what [Ted] Nelson imagined has come to pass. He was wrong about transclusion, wrong about stateful conversations, wrong about how to handle unique IDs, and almost everything that [Tim] Berners-Lee did right -- limited semantics in the application protocol; made it stateless; and created the 404 error, living embodiment of worse is better and savior of scale -- violated Nelson's bankrupt vision. Xanadu was the wrong answer, REST (Representational State Transfer) is the right one. If you thought that all that was wrong with RSS 1.0 is that RDF didn't make it confusing enough, attach the twin boat-anchors of OWL and the Semantic Web to Echo and see what happens.
(paraphrased from my response on the Wiki ;-)
Nelson talked about having "everything" linked together using hypertext. In most important senses that's just what we're getting with the web, the implementation details (404's etc) are secondary. OWL and the SW certainly aren't boat-anchors, because they aren't attached to the boat...it's like saying that Web Services are boat-anchors for XML. The SW technologies allow the creation of applications that should be able to do a lot more with the data generated by Echo feeds, and there's potential for generation of new kinds of feed content there too.