I was reading two days ago an interesting article of Kurt Cagle titled AJAX, Systems Theory and Climate Change. What stops me in the article is that Kurt is a physicist, and it remind me my own cursus of energy engineer, and approaching internet systems with physics laws is really interesting somehow. I talked before about entropy for example and how it could be used to describe systems, if we could assign an entropy to a client/server application we'll notice that this entropy will increase considerably for AJAX systems. I won't talk too much about physics myself but I really suggest you to read the article.

I definitely see AJAX playing into this model because it replaces tightly bound, synchronous services with loosely coupled, declarative asynchronous services on the client, and because of this also shapes the server (and in time servers) development process. It's a regime change, and will likely end up becoming a dominant strange attractor until the system pushes this out in favor of even more effective solutions. A website no longer has a single "home", but instead is made up of components that pull their data from a wide variety of different websites and webservices, running them through a transformation stage on the client to paint the interfaces.

I think that AJAX will eventually fall by the wayside, but it will be replaced by declarative databound objects, possibly along the lines of an XForms or related technology, however, this is simply a refinement of a larger scale movement away from client/server dyads and into multiply connected nexi that just happen to have the characteristics of being displayable (and manipulatable) by people. This will change the "energy" of the web as well.