I'm happy to announce that Mustella is now fully ready for use! All tests are passing on Mac and Windows, including AIR and Mobile test suites.
You'll find Mustella in the "develop" branch of the Apache Flex SVN repository or as part of the Apache Flex source download; Mustella will become part of the next release of Apache Flex. If you haven't done so, you can find out more about Mustella on the Apache Flex Wiki. I want to thank everyone who helped make this a reality. Peter Ent Flex SDK Team Adobe Systems