In State of Ajax: Progress, Challenges, and Implications for SOAs, Dion Hinchcliffe gives his take on just where all the hype and sensation surrounding AJAX is headed. I also editorialized on this subject somewhat in the Tech Times #120.
Despite some claims that AJAX will supercede desktop application development, I believe that certain types of applications are–at least for the forseeable future–inextricably bound to the desktop. That said, thanks to AJAX and its kin, the Web really has grown significantly in the type of user experience it can deliver for the kinds of applications it is suited for.
In his post, Hinchcliffe makes some observations about how the rise of AJAX-style development on the client side will affect some of the trends at the leading edge of server-side development. In particular, he points out that a lot of the new standards being developed for Web Services are not architected such that they will be useful in an AJAX-driven world. Whereas AJAX thrives on many rapid, lightweight, bite-sized communications with a single server, much of the current work on Web Services is towards the exhange and processing of large documents between multiple service providers in a secure and intricately choreographed way.