Simone  has finished the survey and published the results of the survey about the usage of AJAX among .NET web developers . The results are very interesting. The most used AJAX toolkit is ASP.NET AJAX  with about 73.7% followed by the AJAX Control Toolkit  which is used by almost half of the .NET developers that are using AJAX.
The second mosed used framework after the Microsoft one are my Ajax.NET Professional  and jQuery , both used by 13.3% of the users. As I know there are many web developers that are combining jQuery and my lib because they fit together very good.