after several tryings, I finally get ported the audio drive for OSX Lion 64bit, based on the original source codes from http://scifi.pages.at/ffm-2/ for OSX Tiger.
Use KextHelper to install the CMI8738 audio kext or just copy CMI8738AudioDevice.kext to /System/Library/Extensions and type following lines to the terminal:
sudo -i cd /System/Library/Extensions/ chown -R root:wheel CMI8738AudioDevice.kext chmod -R 755 CMI8738AudioDevice.kext
To test it on running system:
Maybe you have to clear your kextcache!
If there are problems to getting work the kext, just ask me
PS: Its a native 64bit kext!