You Know Your Web 2.0 when...
Useful Distinctions in Social Software
Thinking in Web 2.0 Sixteen Ways
But the real point of this post is that Dave's comment...
If you think Learning Management Systems & e-Learning Solutions is heady stuff, take a look at ... (web 2.0 stuff)
I think that pointing folks to Dion's articles that talk about the technical underpinnings will scare people away from Web 2.0. It seems to imply that the relatively simple tools that come under the eLearning 2.0 / Social Software umbrella are complex. As a user of these tools, services, etc. the first thing you notice is that they are QUITE EASY TO USE! And there is no comparison to the complexity of an LMS - which is almost always quite complex.
In fact, I generally think about an LMS and classic eLearning solutions in a completely different way as compared to thinking about Blogs, Wikis, etc.