According to Nature's analysis of the project, just 5% of articles submitted for traditional review also opted for open comment, and that the amount and quality of responses didn't contribute significantly to deciding if a paper was worthy of publication. Some authors worried about getting scooped, others about patent protections. Public comments were sparse, but the effort wasn't ignored: Nature describes the traffic to the pages as "significant," with average of 5,600 page views a week and similar frequency of RSS feeds. Ultimately, Nature concludes in its editorial that "the level of interest in open peer review is too small" to hope to catch cases of fraudulent or weak research, and they won't do open peer review.
John Timmer writes that anonymity was the key ingredient stripped from the online process. Others commentators paint this failure as inevitable, but it hardly strikes me as such, given the strength of the community around Nature. I'd be shocked if some variation-I don't know what, perhaps a more gated online review process, such as allowing anonymous comments by some pre-qualified subset--isn't eventually adopted. Indeed, Nature is getting right back into the game, promising in its editorial to create a forum next year for the kind of public discussion that researchers inevitably engage in after a paper is published:
"If this kind of discussion is to make it into the open, rather than be confined to gossip at conferences, it requires a forum where peers are able to comment on individual papers, with minimal editorial intervention. Would commenting on Nature papers be more widely adopted by researchers after they have been formally published than before? We intend to introduce this function next year, and find out."
Good luck. Anyone looking to generate content from their users and to build a community online should be humbled and impressed by Nature's experience. User-generated content may be the runaway freight train of Web 2.0. That doesn't mean it's easy to jump on.