I've been asking lots of questions about the potentials of Ajax programming to hurt an app, probing various aspects of the potentials for Ajax-style development to impede on a web app's security, true asynchronous development model, scalability, mobile support, the perception of building faux "rich" clients, and other concerns, many of which admittedly stem from my general ignorance. 

Rick Strahl penned an outstanding piece for CODE Magazine objectively and honestly supporting (and in some cases discounting) many of the theories I've developed about the cons of Ajax, looking past the hype-driven pros.  Really good work, attacking the main points one really needs to know when considering an Ajax-enabled architecture.  A must read.

http://www.code-magazine.com/Article.aspx?quickid=050093