Web 2.0 tries to capture some of that delta with its notion of a "Participatory Web" or "Web as Platform". And from an end user and developer perspective, respectively, I think that indeed gets at some of the core elements.
However, from a business and cultural perspective, I think its at once simpler than that and deeper than that. One of the foundational promises of the Internet was in enabling many-to-many communication: arbitrary people connection graphs, if you will - and in large measure, its done that. Websites, homepages, e-mail, IM, message boards, blogs, etc. CONNECT people - IP address and physical location are among the least interesting ways that we address anymore (voice/cel is still key and I think tandem addresses will enable yet another layer of services - more on that another time).
Further, I'd argue that at the core of that networking is Syndication. And yes, I mean syndication in every sense of the word - even social networking is about trust metric driven, loosely coupled, syndication networks, where tagging, rating and social connections drive trust (and therefore traffic). As always though, this works best when greased with the fiscal incentives syndication can drive at scale.
Let me explain (in part 2 :)).