Another interesting Jeff Sutherland's paper on that subject is "Scrum and CMMI Level 5: The Magic Potion for Code Warriors"
Is is said : "Results show that projects combining Agile Methods with CMMI 5 are more successful in producing higher quality software that more effectively meets customer needs at a faster pace."
If you can read french, here's a very good article on that subject : Synergies entre CMMI et les Méthodes Agiles