Here are some of the most important things to know about web 2.0:

Web 2.0 is much more than a term coined by a publisher in 2004.

Web 2.0 changed the way people interact online.

Web 2.0 gave businesses opportunity to lure users to put more information online, the full impact of this is yet to be seen.

Web 2.0 has not figured out solid ways to make money. Users are too busy to look at the ads. Leading web 2.0 sites like Facebook.com or Digg.com are still to make money after almost 5 years in existence. In comparison, Google was making $100 million by the time it was 5 years old.

Barring a few, most web 2.0 companies have features instead of products. Many indeed hoped to be bought out by bigger companies, but instead have been copied.
In the web 2.0 era, starting web companies was cheaper than ever before, as result, more companies crowded the same space.

Web 2.0 gave birth to these terms: social media (all the web 2.0 sites), participatory media, user-generated media - notice, all these terms, there are more, are centered around Participation.

T2D2: A marketing strategy used by web 2.0 startups, which meant depending on mentions from 4 web sources as a big achievement: Techcrunch, Techmeme, Del.icio.us, Digg.

Like the earlier web bubble, web 2.0 gave some people to create buzzwords and sell them to whoever was buying, especially VCs and Big Businesses.
In response to these opportunists, Nicholas Carr once said, " I'm claiming the trademarks on Web 3.0 Conference, Web 3.0 Summit, Web 3.0 Camp, Web 3.0 Uncamp, and Web 3.0 Olde Tyme Hoedown."

The term web 2.0 distracted from the real value happening on the web. - Russell Shaw

The same people who covered the thousandth bookmarking application, without analyzing its chances, are now saying that web 2.0 is dead, based on the simple fact that few people are searching for "web 2.0" .

But, few people search for buzzwords. People search for things and facts.

So, is web 2.0 dead?
The web 2.0 idea of giving users the power to talk back and contribute will become stronger than ever. Companies, newspapers, web sites...all are using web 2.0 tools to create true and full interactive experiences to their customers.

The web 2.0 idea of creating silly buzzwords is sure dead. In fact, they have moved on to Web 3.0.