Hi Jonathan, we got X2Pro up on the Apple Mac App Store
http://itunes.apple.com/us/app/x2pro-audio-convert/id501688639?ls=1&mt=12. It takes the FCPX XML and creates an AAF with all the audio embedded. No levels, automatic gain or fade handles yet, but they should be in an update we'll post in a couple of weeks. Love to hear how it goes.
Chris Steele
Product Manager
Marquis Broadcast