Flex 3 Schema for XML Editors
Because of the large changes in the MXML attributes from Flex 2 to Flex 3, it wasn't possible for me to spend enough time changing the [node:1344] to support the new version.
Fortunately, there is no need for me to do so because the XSD4MXML project has one for download, plus source code to generate it yourself from Adobe's own source code.