The images posted on nin.com on July 16, 2008 show the label on the album which reads "limted edition CD + DVD". It is difficult to make out the smaller print, but it doesn't appear to give any further clues to a 3rd disc.
=====11th Track=====
Amazon.com (US) shows the CD having 11 tracks in the track listed. The 11th track in entitled "Slip". This may be an error much like the apparent 3rd disc.
==Track Listing==