Jason Kelly opened up a page in OpenWetWare for discussion of wiki reviews. Writing a review on the progress of a field could be the most obvious use of collaborative efforts. The reviews could be continually updated and periodic versions could be frozen and submitted to a more conventional repository.
Jason suggests that one way to kick start the process would be to wikify a review published already with an open license and let people update it. OpenWetWare has now over 2000 registered users and continues to grow as probably the best example of online collaborations in science.
If you have ideas about how to implement wiki reviews, or simple want to start writing one, head over there and give it a try.