Nature is investigating the future of peer review. They are hosting a public debate about the value and methods of peer review and are making an experiment with "public peer review":
In Nature's peer review trial, lasting for three months, authors can choose to have their submissions posted on a preprint server for open comments, in parallel with the conventional peer review process. Anyone in the field may then post comments, provided they are prepared to identify themselves. Once the usual confidential peer review process is complete, the public 'open peer review' process will be closed. Nature will report on the results after the trial period is over.
More about open peer review
from O'Reilly's Radar and the Nature page
with more information and links about the debate and the open peer review process.