Good question(s). Web 2.0 is something “some” people have begun referring to as the next “version” of the web. Of course, there is no “new release” that has happened, nor will it happen. Nothing about “the web”, the Internet, etc. will actually get “rolled out” like a software version would be.
However, Web 2.0 is an interesting idea that identifies with some of the capabilities, technologies, and uses that the web has come to allow (which it wasn’t typically known for in the past — perhaps you might call the past Web 1.0). These concepts include more dynamic websites with content tagging capbilities to allow for a richer administration and user experience. For example, this blog would be considered Web 2.0.
There is much more that can be said about Web 2.0, some of which is more technical, but I think it is really up to each of us to determine how far we take the whole Web 2.0 “idea”, since that is all it really is – an idea. Perception is reality as it is said in business, and quite a bit in consulting, so if people perceive a Web 2.0, then I guess it is and/or will be a reality indeed.
Following is an image I found online that helps describe some of the key aspects of Web 2.0. Sometimes a picture is worth a thousand words. In this case, there is no debate since this picture is basically an image of one thousand words (okay, I didn’t count, and yes, it does look like less than 1,000 words, but you get the idea). Note how they are arrayed in a radial, tag-cloud like manner (I have implemented dynamic tag coulds, but it might be interesting to try one that is laid out radially like this on an actual implementation rather than just a static image):