It's not about AJAX, or Widgets… it is about the mobile web “runtime”. The “runtime” is what makes thin clients dynamic and exciting. The “runtime” is what allows for client-side scripting, and AJAX, Widgets, and other methods not invented yet.
The “runtime” and consistency across (mobile web) “runtimes” is what is going to make mobile browsing what needs to be.
The (mobile web) “runtime” doesn't have to be the browser. This is especially true for mobile. This is some of the feedback I sent to Anne van Kesteren of Opera Software, one of the editors of the First Public Working Draft of Widgets 1.0. Read the spec and send your feedback to the editors…
The W3C and Opera Software has taken a first step by defining a baseline for Widgets authoring. The effort must be continued to include access to local functionality, security and permission models, and other. The process must involve companies and individuals beyond Opera Software and Queensland University of Technology. Only then mobile web will rival (in functionality) local/thin mobile applications.
Yes, it is more than just the client-side “runtime”, and it also is about the Web, and services on the web. The mobile web “runtime” is end-to-end.