Clay Shirky has a great new essay The Semantic Web, Syllogism, and Worldview that gives a funny and at the same time brutal critique the Semantic Web.
This is perhaps perhaps the high water mark of presenting trivial problems as worthy of Semantic intervention: a program that can conclude that 102 is greater than 100 is labeled smart. Artificial Intelligence, here we come.
I'd like to note that I've covered this topic before but from a slightly different angle in Meaning, Semantics and RDF. I'd also empahsize the last paragraph of Clay's essay.
Much of the proposed value of the Semantic Web is coming, but it is not coming because of the Semantic Web. The amount of meta-data we generate is increasing dramatically, and it is being exposed for consumption by machines as well as, or instead of, people. But it is being designed a bit at a time, out of self-interest and without regard for global ontology.
Emphasis mine. This is exactly the point I made in The Well-Formed Web, that the value that the proponents of the Semantic Web were offering could be achieved just as well with just XML and HTTP, and we are doing it today with no use of RDF, no need to wait for ubiquitous RDF deployment, no need to wait for RDF parsing and querying tools.