This explains the delay...

Long process leads to short Vista sound

SEATTLE - Some musicians spend 18 months working on a whole album. At Microsoft Corp., that's how long it took to perfect just four seconds of sound.

Of course, this isn't just any four-second clip. It's the sound -- a soft da-dum, da-dumm, with a lush fade-out -- that millions of computer users will hear every day, and perhaps thousands of times in total, when they turn on computers running Microsoft's forthcoming Windows Vista operating system.

To set the right tone -- clean, simple, but with "some long-term legs," according to Microsoft's Steve Ball -- the software maker recruited musician Robert Fripp. ...

There are a total of 45 Vista sounds that Microsoft has spent the last year and a half perfecting, including the dings you hear when you get a new e-mail, receive an error message, or log off your computer. Generally, these are more muted, less jarring variations of the prompts familiar to Windows XP users.

I wonder if they spent 18 months writing the sound drivers?