I think you've misunderstood something you've read. Intel's CPUs do no have video nor audio processing. They may be fast enough to decode H.264 without an external processor (but I'd still prefer to use the one in the video card), but there's nothing dedicated on the CPU (actually there's nothing dedicated on the GPU either, but I like to off-load what ever processing I can).
Windows 7 still has the software mixer. It's obvious when you can control the volume of each individual program that's producing sound. There was a stink from a very vocal minority, they were quickly forgotten. Though there was a consolation, an API was provided for programs who want to bitstream, but they have to be specifically written to do so. If they just open the Windows audio device and start playing sound, they'll get the new mixer.
