Curiosity seems to be the driving force behind the prevalent nonfiction writers mentioned in both introductions. A continuous curiosity for the larger meaning of a story, one that can't be quenched with the normal constraints of a daily newspaper.
I liked Katherine Boo's entry in Telling True Stories about riding buses around neighborhoods that you don't know well even though it might take some "subversion of your editors." The openness she implies by "reporting by not preparing" and being ready to hop a bus to Georgia if the story dictates intrigues me. The flexibility of not being told where the story is and how it is supposed to be reported makes narrative journalism exciting to me.
The New Kings of Nonfiction has already caught my attention after reading only the introduction, but I may be biased because I am a fan of Glass' This American Life. All of the examples he puts forth in the introduction are entertaining. Not only do the authors have fun putting themselves in others shoes researching the story, they try to make serious issues entertaining to read. This seems to be a valuable instrument in making important issues known.