As I note in the release teaser, "This release of the AJAX Control Toolkit includes four new controls (AutoComplete (formerly in the Futures CTP), Calendar, MaskedEdit, and Tabs), fixes for over 75 issues reported by the community, and new functionality for ModalPopup, RoundedCorners, and the ExtenderBase framework." Additionally, we spent time making sure that all 32 Toolkit controls work well on the latest version of the Opera browser. Accepting that every browser has its little quirks, we now offer the same level of "pretty much everything works" support for Internet Explorer 6, Internet Explorer 7, Firefox 1.5, Firefox 2.0, Safari 2.0.4, and Opera 9.10. Those are the top six browsers on the Internet, so there's an very good chance that visitors to a Toolkit-enabled site will be running a supported browser.
Of note, three of the four new controls for this release were submitted by contributors! Ron Buckton wrote both Calendar and Tabs while Fernando Cerqueira wrote MaskedEdit. These are some very cool new controls and we're fortunate to have such great contributors helping out with the Toolkit! As a teaser, I created two little "movies" to show off Calendar and MaskedEdit in action - as well as our Opera support. :)
Recall that you can sample any of the controls right now (no install required). You can also browse the project web site, download the latest Toolkit, and start creating your own controls and/or contributing to the project!