Looks like there could be more incentive to use an API besides Direct X, at least for audio. Microsoft will be removing DirectSound 3D Hardware support from Direct X with the launch of Windows Vista. DirectSound and DirectSound3D will still function; however, they will no longer use hardware acceleration. Here is where OpenAL, a cross-platform 3D audio API appropriate for use with gaming applications and many other types of audio applications, can step into the spotlight. It's already attracting attention among developers. A list of some applications using OpenAL can be found
here.
http://www.openal.org/openal_vista.html Link To Original Article