When a development team is following XP Principles, mostly two developers are doing Pair Programming with Test Driven Development (TDD) and rotating pairs every week, how much value will it add with code review ? We recently had a discussion where some of us think it is still good to skim through the change request by a second pair while other's think it's just a waste of time.

I am curious to know if code review is encouraged by a second pair in following XP practices ?