Just started using this app and have to say I'm impressed. Often these audio or video apps say they do something but then do it badly or charge you obscene amounts of money for something you would this is relatively simple (especially with CoreAudio). I could be wrong there though... :)

One thing: interface. Just needs a window to open when you open the app. Otherwise users need to go searching for how to use this app. Would be nice to have an open list box when you start the app and then just drag all the files you want to convert and click convert :)