I’ve been using an internal beta of Fireworks CS3 for several weeks now to wireframe Flex projects, and let me just say… Fireworks CS3 rocks. Particularly with the new Flex components library that comes with Fireworks CS3, and the pages feature that allows me to specify which layers are shared across which pages, the time it takes me to develop wireframes has literally been cut in half, leaving me more time to actually focus on designing the best user-experience.
I wrote up an article with one possible workflow using the Fireworks to design, style and skin a Flex application. You can read the article here at the Fireworks Developer Network.
What’s more, with Fireworks CS3 including a AS3 engine, I’ve packaged the Flex Style Explorer as a Fireworks Extension that will run directly in Fireworks. You can download and install the MXP here.
Fireworks CS3 is required.