After the experience with the Post-GWAS article on WikiGenes I started looking at the resources on Nature Precedings, which is where the original idea of that collaborative article came from.
Nature Precedings is a Nature Network website where researchers can post drafts, ideas, presentations about work that can be published. This is exactly what I suspect has happened for the WikiGene article: the authors from the Post-GWAS consortium published a draft of a letter there, and the letter has been noted by some Nature editor, who suggested it to transform into an article and to open it to a collaborative editing.
I am looking at the presentations on Nature Precedings and thinking that maybe, some of the presentations I made or attended may be posted there. It is not very clear how the requisite for publication there are interpreted: most of the documents present pre-print papers and drafts, but some of the presentations illustrate software tools that have been published.
In any case, I think I will start putting something there… I have some ideas that I do not have the time to develop by myself, maybe if I upload them there, I can find somebody wishing to collaborate with me.