Source -http://webtrends.about.com/od/web20/a/what-is-web-30.htm -
Having answered "What is Web 3.0?", we proceed to the much more difficult question, "What will Web 3.0 be?" The truth is that predicting the Web 3.0 future is a guessing game. A fundamental change in how we use the web could be based on an evolution of how we are using the web now, a breakthrough in web technology, or just a technological breakthrough in general.
But, we can nail down some likely scenarios.
Web 3.0 as a Marketing Term. Sadly, this is probably the most likely way that we'll be using the term 'Web 3.0' in the future. Web 2.0 has already achieved monumental buzz, and '2.0' has already been attached to Office 2.0, Enterprise 2.0, Mobile 2.0, Shopping 2.0, etc. As the Web 2.0 buzz declines, we will probably be seeing websites popping up claiming to be 'Web 3.0' hoping to create a new buzz.
The Artificially Intelligent Web 3.0. Many people ponder the use of advanced artificial intelligence as the next big breakthrough on the web. One of the chief advantages of social media is that it factors in human intelligence.
For example, social bookmarking as a search engine can provide more intelligent results than using Google. You are getting websites that have been voted on by humans, so you have a better chance at hitting a good website.
However, because of the human factor, the results can also be manipulated. A group of people could vote for a particular websites or article with the intent of making it more popular. So, if artificial intelligence can learn how to separate the good from the bad, it could produce results similar to social bookmarking and social news sites while eliminating some of the bad elements.
The Web 3.0 Semantic Web. There is already a lot of work going into the idea of a semantic web, which is a web where all information is categorized and stored in such a way that a computer can understand it as well as a human. Many view this as a combination of artificial intelligence and the semantic web. The semantic web will teach the computer what the data means, and this will evolve into artificial intelligence that can utilize that information.
The World Wide Virtual Web 3.0. This is a bit more of a far-fetched idea, but some have speculated that the popularity of virtual worlds and massively online games like World of Warcraft might lead to a web based on a virtual world. Kinset recently created a virtual shopping mall where users can walk into different stores and see the shelves populated with products. It isn't a far stretch to see this expanded into an idea where users can interact with each other and walk into a wide variety of buildings, some of which might not even sell anything.
But, the idea that the entire web would evolve into one single virtual world with buildings, shops, and other areas to explore and people to interact with -- while not unbelievable in a technological sense -- has more than just technological hurdles to overcome. The virtual web would need to get the major websites on board and agreeing to standards that would allow multiple companies to provide clients which, no doubt, would lead to some clients offering features that other clients don't offer and fierce competition between clients.
It would also increase the time it took to bring a website into the virtual web since the programming and graphical design would be much more complex. This extra expense would probably be too much for smaller companies and websites.
This virtual web presents a few too many obstacles, but it should be kept in mind as a possible Web 4.0.
The Ever-Present Web 3.0. Not so much a prediction of what the Web 3.0 future holds so much as the catalyst that will bring it about, the ever-present Web 3.0 has to do with the increasing popularity of mobile Internet devices and the merger of entertainment systems and the Web.
The merger of computers as a source for music, movies, and more puts the Internet at the center of both our work and our play. Within a decade, Internet access on our mobile devices (cell phones, smartphones, pocket pcs) will be as popular as text messaging. This will make the Internet always present in our lives: at work, at home, on the road, out to dinner, wherever we go, the Internet will be there.
This may very well evolve into some interesting ways in which the Internet will be used in the future.