After some investigation it appears SHIV will continue to use Direct Sound as SHIII did but with probable improvements (similar to the graphical enhancements maybe?). It
will not use Xact audio (YAY for W2K users!

). I didn't know this before hand, but Xact is the audio engine for Xbox. The reason it's usable on the PC (or on XP in this case) is because it was ported with Blazing Angels to a PC format. Makes sense I guess.
Good. I can hang on to Windows 2000 Pro for at least one more game. Hehe.