The Gartner Hype Cycle for Emerging Technologies 2008, which is illustrated below, is a graphic representation of the maturity, adoption and business application of specific technologies. The hype cycle also shows how and when technologies move beyond the hype, offer practical benefits and become widely accepted.
In this Gartner press release, I read that Web 2.0 will emerge within two years to have transformational impact, as companies steadily gain more experience and success with both the technologies and the cultural implications.
Note, for example, how far corporate blogging is.
You can listen to a 12½ minute discussion on the topic between Gartner analysts Jeff Comport and Jackie Fenn by clicking here.