Stephen Downs wrote a very nice overview paper about E-Learning 2.0 and its trends. In that, he describes the evolution of Web 1.0 to Web 2.0 and maps the process to the evolution of e-learning by identifying Web 2.0 patterns and explaining how to use them in e-learning. Here are few nice quotes:

•  ”People in networked markets have figured out that they get far better information and support from one another than from vendors.”
• “… the structures and organization that characterized life prior to the Internet are breaking down.”
• ” … the Web itself was being transformed from what was called “the Read Web” to the “Read-Write Web,” in accordance with Tim Berners-Lee’s original vision.”
• “In a nutshell, what was happening was that the Web was shifting from being a medium, in which information was transmitted and consumed, into being a platform, in which content was created, shared, remixed, repurposed, and passed along.”
• “… Web 2.0 is not a technological revolution, it is a social revolution. [...] Web 2.0 is an attitude not a technology. It’s about enabling and encouraging participation through open applications and services. By open I mean technically open with appropriate APIs but also, more importantly, socially open, with rights granted to use the content in new and exciting contexts.”
• “… online learning software ceases to be a type of content-consumption tool, where learning is delivered, and becomes more like a content-authoring tool, where learning is created
• “It also begins to look like a personal portfolio tool.”
• “… e-learning content is syndicated …”
• In a ubiquitous computing world, we expect to “have learning available no matter what we are doing.”