Select your version and go. This version supports D3 so you can extract whatever you want. Creature sounds, world ambience, spell effects, class/gender-specific lines to create your own audio porn or unnecessary censorship vids lol. I hear people particularly enjoy the soundwork of Diablo 3, now they can have it. Or, in my case, get that particularly awesome music clip that plays back outside of the Spire portal right before you enter to face Diablo himself.
Did you know there are actually 2 versions of that? In the Collector's Edition OST it's actually the last minute of the "Heaven's Gate" track. But in the mpq file the two versions are on their own, which is just what I wanted. Or maybe BrotherLaz can get some graphics to create his own version of D3 in D2 engine
There are also many .fsb files, which are like archives for sound files, a format also used in Crysis 2. You can open those with a Java-based program called MusicPlayerEX. Once you open the fsb file, it will automatically load the containing audio files in a playlist. You can then convert them to whatever format you wish.
PS: I know it's called "editor" but I wouldn't edit anything if I were you, unless you wanna get banned.