I my recent blog posts (Web 2.0 vs Web 1.0 that's the question and Page flow with dojo) I have adressed the Web 2.0 / Rich Client Approach.
I then decided to figure it out by doing a POC and a demo application. I'm working with setting ut a Confluence Space regarding this. As there is a lot of clever and helpful peple out on the net, I am inviting everyone to visit, learn, contribute to my project.
Read more here : Home of the Rich Client POC