Disk two is a collection of new songs with guest singers for every track.
I bought this for the disk 1 "hits", but after numerous listens of both disks, I would now have to say I love disk 2 even more. Disk two has a few death metal songs (eg. track 1 - Repressed), which I don't really care for, but it is filled with amazingly haunting and beautiful songs featuring an array of international artists from a variety of countries. My favourite song is track 4 - Hope, Vol.2.
I highly recommend this double-disk set for a great introduction to the bands instrumental-cello-metal wickedness, while the second disk will be a pleasant surprise as well.