I couldn't agree more with David Weinberger - these notes on what it is we want from the semantic web are great. There's a human thought mode that just clicks with The Web's organization (unsurprising, since The Web was made for it) - one is tempted to paraphrase the Apple slogan to characterize the way it works : "Scan. Jump. Learn".
Burningbirds objection to the Semantic Web Vision is related to the Personalized vs Customized distinction. The usual Semantic Web dream is one of "smart environments" - and that's just not what we want. We want to be smarter ourselves. We want to preserve the notion that we are the ones acting on our environment. We do not want the environment to act on our behalf.