Amethyst is a Flash/Flex/AIR/ActionScript visual design, coding and debugging environment for Visual Studio 2008 and 2010. It has all the things you’d expect from a VS IDE - drag+drop, click+code, IntelliSense, drilldown debugging, customizable code formatting, refactoring and so on.
Anyway, if you want to find out more or download the release candidate, head over to the SapphireSteel Software web site: http://www.sapphiresteel.com/Blog/article/amethyst-release-candidate-1