There has been a lot of talk lately about sound in Windows Vista.
Recently Robert Scoble talked with Steve Ball, Group Program Manager for the Windows Audio/Video Excellence Team regarding plans to hard-code the start-up sound played just before the OS is ready for the user to log on to their PC. To elaborate: right before the log on screen appears in Windows Vista, an animation of the new Windows "orb" appears with a non-customizable start-up sound. The idea behind this is that it will help the PC user know that their sound is working correctly, its current volume setting, and that the PC is prepped for music and video playback upon log-in. The Xbox 360 does the same thing when it boots up -- a hard-coded start-up sound. Steve explains the idea in more detail at the above post.
Also: Amir Majidimehr, a digital media expert and MS Corporate Vice President, explains audio processing in Windows Vista at the AV Science forum and details some cool changes coming in the Windows Vista sound stack.
Lastly, I should point you to this fantastic new whitepaper on the audio subsystem advances made in Windows Vista -- it really does a excellent job of elaborating on many of the changes and new features that Amir mentions in his forum post.
Windows Vista is starting to sound better and better ...