The Wikipedia text you have for Rahat Nusrat Fateh Ali Khan is mistaken. You accidentally took the bio of his uncle, Nusrat Fateh Ali Khan who died in 1997.
Rahat is his successor in this spiritual form of Sufi music called Qawwali (which finds its home in Pakistan and India). James Horner used Rahat in the score of "The Four Feathers."
Although in "The Four Feathers" he was used more "intensely" than typical Qawwali, you can see him performing Qawwali here [YouTube link].
There is a short bio of him at Wikipedia here and Answers.com here.
Also, this website has some good information.
It will be interesting to hear how Horner uses him in "Apocalypto" since he has a distinctly Persian/Indian sound. But as I said, in "The Four Feathers," he sounded very intense and ancient - though that film was a British and Muslim film so he fit perfectly. Nevertheless, if he's used properly (which I'm sure Horner has done), he will bring a very "dark and ancient" feel to the primitive sounding score.
Thanks for the excellent research, Antonius!