I'd love to hear if you are able to get the VFS mapping module to work. Using version 1.1 requires samba 2.1.12 or so, and the v3 one worked (after some effort) with samba 3.0. However, neither WinAmp nor MediaPlayer would work, as they check the wav file's size, and then only play that much, bonking out when the bytes have been read, even though there is much more data to be read from the wav file being handed down.
I was considering doing something stupid like making fstat return twice or three times the size of the .flac, since (for me anyway) it gets about 50% compression rates.
Please let me know if you have better luck! I sent email to the original author, and to the guy that ported the v3 stuff, neither answered.