Here we go again.
you could theoretically make a 32 bit mp3. But it will be bigger than a wave file, which kinda defeats the purpose for even making a mp3 file (remember mp3 are suppose to be a compressed file).
now there are some guys here (me, Crysalis, Dj Chris and Molson) that really know audio and we have enough sense to not believe everything that is put on paper about it
the stuff that they are promoting with the x-fi card is bullship. they are taking into consideration that most people don't know audio and they will believe anything that they read.
the x-fi card is a sound card with ram and an eq circuit. nothing more, nothing less