Flex Builder is being renamed to Flash Builder! As a teacher of a Flash class who fields questions about the Flex Framework vs. Flex Builder and “what exactly is the Flash Platform,” I think this is great. In time, I think this will lead to less confusion. Flash Builder will compile to an SWF that runs in the Flash Player; not that Flex Builder didn’t before, but having a the similar names is more intuitive. In addition, the Flash Platform will be consistent, all having Flash in all their names - Flash CS4 Professional, Flash Catalyst and Flash Builder.
In the words of Ryan Stewart, “the developers to the platform will use Flash Builder, the designers can use Flash Catalyst, and those of you who are creative developer rockstars will continue to use Flash Professional to create some great content.”