The Mac OS X package for FlightGear 0.9.9 has now been released and is available now right here.
It's been almost a year since the first MacFlightGear release and a lot has changed. The main OSX flight starter has been rewritten for added stability, the core libraries have been ported to universal binary, there's an option to download new scenery in the background, and the ability to define other advanced options.
Much has also changed in the flight simulator. For more information on that see www.flightgear.org