The 70MB download features the entire track, broken off into 64 sections, with all the core sound libraries and six different, increasingly more intense, versions of the song's chorus. Fans can toy with the files at will, and can even take song sections and utilize them as the foundation from which they can create their own songs. Or they can just mess with Reznor's vocals, as he suggests.
At a time where so many in the entertainment world seem to be trying to keep music away from the internet, this is welcome news. Reznor is really being quite progressive here in his offering of the track in this way.