Of course, any software engineering theory dictates that any AJAX should have no trace of business logic, but that this one must be limited to the server. Any good developer will tell you that one should put all of your logic in server-side web services, and handle only the presentation issues on the AJAX client side.
Some day there will be such a platform, well beyond AJAX. However, it will be also thanks to AJAX.
jcamara at softwareag dot eshttp://www.bloglines.com/blog/jcamara