I have to admit I'm still finding small bits of functionality that I didn't know about and that makes me smile. It's the attention to detail that makes me feel proud to be associated with such a quality product. Take for instance today when I plugged in my headphones to listen to some non-DRM'd music using Windows Media Player. Before I plugged in the headphones, the playback devices were listed as in the screenshot on the left. Vista recognised immediately when I plugged in the headphones and the list changed to the screenshot on the right.
I then have the ability to configure the headphones, setting things like volume (independent to other output devices), the icon, sound enhancements like:
It even tells me which jack to plug the headphones in - nice touch.
I agree, the new audio stack is a great great improvement over the previous versions of Windows; relly apprecate the way we can better control application volumes individually etc. Love the headphone icons too ;-)!