AJAX is not a new technology, it was not invented recently, and it is a great Venture Capital magnet. However, it is not the technology aspect what defines the barriers to enter the AJAX market, but the overall vision of architecture change that an RIA involves. An _AJAX_ expect is not who knows JavaScript, but the one who can design an interactive user experience that will attract new customers without becoming too complicated for the existing ones.

Now in a technical point of view, the common JavaScript developer will leave all the business logic in the client side, jeopardizing the entire application, leaving your soul exposed. What has evolved in the last year is applying common object oriented programming and design patterns to maintain your core business logic in the server, and leave only connectivity scripts in the client side, hence, creating enterprise level AJAX sites.

Microsoft released their first take integrating AJAX to the .NET framework, aka 'Atlas'.

"Nikhil Kothari provides a brief overview of ASP.NET "Atlas", a framework to build rich Web apps on top of ASP.NET 2.0. The demo shows an app that uses the new server controls from the December CTP to incrementally enrich standard ASP.NET pages and an app that shows client-centric app development."