Many people have requested this graph and so I am posting my latest version of it. The Metaweb is the coming "intelligent Web" that is evolving from the convergence of the Web, Social Software and the Semantic Web. The Metaweb is starting to emerge as we shift from a Web focused on information to a Web focused on relationships between things --- what I call "The Relationship Web" or the "Relationship Revolution."
We see early signs of this shift to a Web of relationships in the sudden growth of social networking systems. As the semantics of these relationships continue to evolve the richness of the "arcs" will begin to rival that of the "nodes" that make up the network.
This is similar to the human brain -- individual neurons are not particularly important or effective on their own, rather it is the vast networks of relationships that connect them that encode knowledge and ultimately enable intelligence. And like the human brain, in the future Metaweb, technologies will emerge to enable the equivalent of "spreading activation" to propagate across the network of nodes and arcs. This will provide a means of automatically growing links, weighting links, making recommendations, and learning across distributed graphs of nodes and links. This may resemble a sort of "Hebbian learning" across the link structure of the network -- enhancing the strength of frequently used connections and dampening less used links, and even growing new transitive links when appropriate.
As the intelligence with which such processes unfolds, in a totally decentralized and grassroots manner, we will begin to see signs of emergent "transhuman" intelligences on the network. Web services are the beginning of this -- but imagine if they were connected to autonomous intelligent agents, roaming the network and able to interact with one another, Web sites, and even people. These next-layer intelligences will begin to function as brokers, associators, editors, publishers, recommenders, advertisers, researchers, defenders, buyers, sellers, monitors, aggregators, distributors, integrators, translators, and also as knowledge-stewards responsible for constantly improving the structure and quality of subsets of the Web that they oversee. And while many of these agents will be able to interact intelligently with humans, not all of them will -- most will probably just have interfaces for interacting with other agents.
Vast systems of "hybrid intelligence" (humans + intelligent software) will form -- for example, next-generation communities that intelligently self-organize around emerging topics and trends, smart marketplaces that self-optimize to reduce the cost of transactions for their participants, 'group minds' and 'enterprise minds' that embody and manage the collective cognitiion of teams and organizations, and knowledge networks that function to enable distributed collective intelligence among networks of indivdiuals, across communities and business-relationships.
As the network becomes increasingly autonomous and self-organizing we may say that the network-as-a-whole is becoming "intelligent." But it will be several steps beyond that before it finally "wakes up" -- when the various processes of the network reach that point at which the entire system truly functions as a coordinated, self-aware intelligence. This will require the formation of many higher layers of intelligence -- leading to something that functions like the cerebral cortex in humans. It will also require something that functions as its virtual "self-awareness" -- an internal process of meta-level self-representation, self-projection, self-feedback, self-analysis and self-improvement within the network. For a map of how this may actually unfold over time we might look at the evolutionary history of nervous systems on Earth.
As structures that provide virtual higher-order cognition and self-awareness to the network emerge, connect to one another, and gain sophistication, the Global Brain will self-organize into a Global Mind -- the intelligence of the whole will begin to outpace the intelligence of any of its parts and thus it will cross the threshold from being just a "bunch of interacting parts" to "a new higher-order whole" in its own right -- a global intelligent Metaweb for our planet.