Ajax Extensions ("Atlas") Beta 1
Microsoft has officially released AJAX Extensions Beta 1. Scott Gu has a great overview of the changes (change log) for the beta. In particular there were changes made to the UpdatePanel that will affect just about every webcontrol out there. In prior CTP versions of the UpdatePanel, there was a lot of crafty guess work required to make it work with other controls. Unfortunately, by making too many assumptions to allow for the unknown universe, the UpdatePanel's code stability suffered.
The beta now requires a stricter contract model, which forces controls to register with the UpdatePanel in order to work inside of it. The change is for the better, and should certainly help improve the overall code quality and usability of the UpdatePanel - which is obviously a plus. On the negative side, it will require any component author to make some code changes in order to be compatible with the UpdatePanel. As you would expect, we are already working on these changes, and are pretty close to having a set of compatible bits ready for download. I'll keep you posted and let you know when and where these bits are made available.