The biggest thing I liked was that it didn't just focus on XP, but also hit on a lot of other methodologies, doing some comparisons and contrasts. Expect to understand what all the hubub is about after going through it, without needing to buy into any of the other Agile background books first. You will probably also be able to take away a high-level piece or two of advice from it.
It's not something I would purchase, though, because it stays pretty high-level through much of the book, and doesn't really have much reference material value. I was also a bit dismayed that he hadn't run a project with XP yet. He cheerfully admitted it in the introduction, and his reviewers were all of the hardcore folks associated with XP; however, that still gave me the same feeling as I would get reading a book entitled Questioning Low-Fat Recipies from the Two Fat Ladies, where they claimed they'd never tried any. Sure, they're FAR better cooks than I am. And probably see more different types of recipies in a given week than I will in a year. But I just would get the feeling I might be missing the whole picture and that too many of the judgements are value-laden and not backed by concrete examples of things that went wrong in his XP projects.
Also, it was weird for a book this small, but I felt like it repeated itself in a couple of the 'summary' end of chapter sections, especially near the end of the book.