I recently came across the problem having an Accordion control on my site and wanted to load the pane content on demand to reduce loading time of the site. The Accordion was bound to a datasource and every pane should display data of another datasource. Databinding everything from the start led to an unacceptable load time of the page itself.
Yippie the AJAX Control Toolkit for both .NET 3.5 and 2.0 was released. Some cool features made it into this release like visible=true/false property for tab control and many fixes were done. The 20229 release is now available on codeplex. Great work guys thank you very very much.