Open your eyes - the WAV codecs are here and work well on the device. I tested them when developing the prototype of my recaller widget. The problem is probably that media player / tracker / mafw is not properly configured, therefore doesn't recognize them and you can't play them back through it.
You can however easily listen to a .WAV using a simple "gst-launch playbin2" command in X-Term, e.g." gst-launch playbin2
uri=file:///path/to/your/file.wav"