The current movement towards AJAX is a good thing. If it really were a movement towards AJAX. In my eyes it is rather a higher acceptance for Javascript applications. Of course, it is quite naturally in the early stages of a �hyped� technology to observe many misuses; they use AJAX just for the sake of using AJAX.
I think that the current usage of AJAX is a misuse of the browser. They are designed to render web pages (i.e. (X)HTML pages). Javascript is a bonus. Large data strucures can slow down browsers enourmously (they are still interpreting Javascript just in time).
Alexander Kirk's Blog: 
