Tim O'Reilly coined and "trade-marked" the term Web 2.0. Over the years, Web 2.0 became the most overused term, in an attempt to cover up the massive bust of 2000 for fundraising and justifying hyped-up valuation (like Youtube and to a large extent most related companies).
Maybe it is the mortgage related credit crunch that is clearing the fog. Steve Rubel indicated that most of Web 2.0 are after the almighty dollar. Chris Shipley declared Web 2.0 is so last version. Followed by GigaOm reporting (with a graph that reminds us of Lotus 123 from 1991!) that Kleiner Perkins would not be funding any more Web 2.0 companies.
Web 2.0 is another term for another social company with Ajax funneling data back and forth. Anyone who has used Ajax applications will be able to tell about the lack of performance (New Yahoo Mail, Google Docs & Spreadsheets, EditGrid, the lists goes on (See footnote 1)) and the ubiquitous waiting for server messages. And hung clients.
Web 2.0 is dead because it was a shallow term coined to just say something was different. The technology it was based on was too small to be even significant. Dynamic updating of webpages with pull technology - how fancy is that?
Some try to define the next generation as partly the Semantic Web (the RDL, Ontology, Modal Logic, Axiology sequence) - which is yet another attempt at recreating the twice failed artificial intelligence. However, it is clear that the likelihood of the real semantic web is miniscule - because just by its definition if it ever does work as nicely as promised, all NP complete problems would all be then solved too.
The fundamental nature of software and internet interfaces are changing. There are new seamless structures of data, interaction, organization that has such appeal that it questions the way we do everything.
For example, we are comfortable with Office applications where Word is good at composing, Excel is good at calculating, Powerpoint is good at presenting, and Visio is good at drawing. But none of these is good at what the others do. And this has been going on for the last 10 years.
The next generation wants to do it all in one place. Nay, they have to do it all without having to learn 10 interfaces.
We need to make it happen. Web 2.0 is now officially dead.
Footnote 1. Google Maps, one of the few good later-generation apps, is truly not a massively Ajax application. It evaluates hyperlinks (.gif pieces, which is then rendered onto the dhtml canvas directly without a server passthrough). There is some minor Geocoding, which could be offline calls, but that cannot be counted as serious AJAX - or Web 2.0.