Fellow platform evangelist Lee Brimelow is a die-hard Flash user. But even Lee acknowledges that sometimes Flex is the best tool for the job, and he has just posted a video tutorial, targeted at Flash users, on getting started with Flex.
Michael Chaize is an Adobe Consultant in France, and he also teaches Flex in a school in Paris. He recently ran an "AIR Idol" contest for his students, and the apps they built are really impressive. The students have also published the applications they developed during 2008. Good stuff!
I previously mentioned Amethyst, SapphireSteel's upcoming Flex Visual Studio plug-in. SapphireSteel has just posted a demo of their Visual Designer, an interactive Flex page layout UI that will be part of Amethyst Professional.