EN: As announced on Nasecent the preprint-server Nature Preceedings is officially launched now:

Nature Precedings is a place for researchers to share pre-publication research, unpublished manuscripts, presentations, posters, white papers, technical papers, supplementary findings, and other scientific documents. Submissions are screened by our professional curation team for relevance and quality, but are not subjected to peer review.

Pedro who tested it already for some month as a beta user reported some days ago about it. His earlier post regarding policies of journals regarding preprint-server might take some fears away. Some of the usual suspects have already added documents.