What's the Semantic Web got to do with GIS?

A few years ago there was a lot of discussion about the Semantic Web. Are any of the concepts underlying the Semantic Web coming into fruition with respect to GIS? Or is it just another hippie dream?

I have a dream for the Web [in which computers] become capable of
analyzing all the data on the Web – the content, links, and
transactions between people and computers. A ‘Semantic Web’, which
should make this possible, has yet to emerge, but when it does, the
day-to-day mechanisms of trade, bureaucracy and our daily lives will
be handled by machines talking to machines. The ‘intelligent agents’
people have touted for ages will finally materialize.
– Tim Berners-Lee

Sounds like Tim may have been fishing the same streams as Richard Brautigan, whose poem published in 1963, All Watched Over by Machines of Loving Grace has everything but the cloud:

I'd like to think (and
the soner the better!)
of a cybernetic meadow
where mammals and computers
live together in mutually
programming harmony
like pure water
touching clear sky.