Right now there's no handy tool for that. I have a decoder that runs through the whole .aw and decodes it (dumpaw, but the data is afc encoded, which uses 9 byte frames, but the samples are padded out to be aligned on 16 byte intervals. This means that the decoder will usually lose alignment after playing a particular sample. dumpaw sort of gets around this by decoding the whole file 9 times, so in one of the .wavs it dumps the decode will work for a particular sample.
HOWEVER, this does not work for stereo.
The Wind Waker and Twilight Princess stuff (which also didn't work for stereo) worked because I'd gone through and parsed the archives which describe where each sample starts.
I tried using this for the .aw files that I extracted from Super Mario Galaxy, but it seems to have not worked. I dragged the .aw file into the application, the computer sounded like it was working, but then it stopped and nothing happened as a result. Is there something I need to do or add to make it work for me?