Its essentially pointless, I'd doubt if anyone could tell the difference between equal accuracy 16 and 24 bit systems for music playback. 24 bit is popular in studios where low level dynamics are readily captured but then are usually compressed so they will be resolved on 16 bit playback.
Minute level dynamics is all that bit depth really has much to do with and how many tracks that you listen to would you say have these? The answer with a lot of modern music is that 12 or 8 bit even could sound the same!
As comparison 8 bit offers 256 levels, 16 bit offers 65,536, 24 bit 16,777,216 so 32 bit will offer a ludicrous 4,294,967,296 in theory! Aside from anything else something like this is virtually impossible to manufacture (wrt DAC and ADC's). It's only implementation may be in audio processing, such as a 32 bit VST reverb effect. This is still rather pointless imo as it will eventually be sent out through at best a 24 bit DAC thus loosing the potentially better low level dynamics (and if that 24 bit claimed DAC is on a typical creative card then its mediocre manufacturing tolerences will bring it down to about 18-20 bit worth of relevant detail).
