For physics and astronomy, there is the arXiv. Essentially all the papers (at least for astronomy) are posted there. The next step would be to add a community voting/vetting scheme on top of that. Statistics could be displayed alongside the article, and access to more detailed comments could be facilitated. Version tracking would enable people to update their papers to address criticism and suggestions. (arXiv already does allow people to replace their papers with new versions, and they retain the old ones, but there isn't really an easy way to "diff" two versions of the paper).