Importing SWF 9 Assets From Flash CS3 into Flex

The Flex Component Kit for Flash CS3 lets you create interactive, animated content in Flash, and use it in Flex as a Flex component. These components work with Flex features such as view states and transitions, skinning, and tool tips. The content can be used as a child of a Flex container, or as a skin for any Flex component.

You can download and install the Flex Component Kit for Flash CS3, and the associated documentation, from Adobe labs here.