If you use Linux then I have good news for you: we just released (November 24th 2009) a new version of the Flex Builder 3 plug-in for Linux. You can grab the bits from here.
There are no new features added to this update. However this version was tested on the latest Linux distros and the hardcoded expiration time has been extended beyond December 1st (this is the timeout for the previous release).
Click here to see the release notes.