A couple of articles from sites associated with Codeguru:

AJAX: Asynchronous Java + XML?
Gmail, GoogleSuggest, and GoogleMap opened the eyes for millions of netizens to a "new" Web: a smarter, more responsive, and more interactive Web that does not employ a foolhardy "click, wait, and refresh" approach.

Top Ten Reasons AJAX is Here to Stay
It's an understatement to say that AJAX is hot right now. There's a lot of hype; no one can argue that. It went from a geek buzzword in February to being profiled on CNN in October.

Will AJAX Replace the Desktop?

There is some debate brewing over whether AJAX will replace desktop applications. The two camps are starting to form. My belief and the argument that I am making in this article is: AJAX is not likely to replace desktop applications; but it will give birth to a new breed of software applications.

Creating a Double-Combo Linked List with Ajax
If you have ever shopped for a new shirt online, you may have run into the following problem. You pick the shirt size from one drop-down list, and from the next drop-down list you select the color.

Measuring the Benefits of Ajax
There's a lot of hype surrounding the latest Web development craze, Ajax (Asynchronous JavaScript and XML), and a considerable amount of skepticism about its usefulness in the business realm. Surprisingly, although there is a lot of talk about what amazing things you can do with this approach, there is very little information about the applicability to business.

There are other AJAX articles on Developer.com and DevX as well.