Here's a book that looks interesting: Extreme Programming Refactored: The Case Against XP (courtesy of Mehran).  It seems to be based on an article availabe on the Software Reality website. I think its a positive step to see some critical reflection on XP, as I've had too many conversations about XP that sound like religious discussions.  I've ordered the book, but based on the article it looks pretty funny and as if it has some interesting points (can a customer afford to let a good person spend 100% of their time with the XP team?  How does pair programming allow a developer to think and reflect and achieve a state of flow necessary to understand some problems?).  Should make the next Extreme Tuesday Club meeting interesting ...