I just committed the new NSSound implementation. Keep in mind it's very rough at this point. A few things, off the top of my head:
* Need to check for libsndfile and libao, and only build SndfileSource and AudioOutputSink if they exist;
* There's a hack in Sounds/GNUmakefile or else I could not get this thing to build; * Incorporate David C.'s suggestions.
This thing needs lots of testing. I'll post my test app tomorrow (I'm pretty tired now) so you all can try it, too.