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Just keep in mind that Nature is also a for-profit journal, owned and operated by a large publishing company (NPG, owned by the von Holtzprinck pubishing group) that does not support open access in any way. Wiley and Elsevier (and NPG) have exploited the market for a long time, but most of the top journals, like Nature (NPG) and Cell (Elsevier) remain the most highly respected in the field and--frankly--the ones in which the publications that make or break careers appear.
The PLoS model is not yet sustainable. By Nature's own (possibly flawed) accounting, open access will cost nearly $5000/paper to sustain. With NIH funding decreasing (in real dollars), the push for open access is only going to work if the editoral process is abolished. Quality control does matter.
I support--and publish--open access research. But this simplistic analysis does not service to anyone. What the author might want to mention is that many publishers already comply with the current NIH policy of making all research papers freely available 6 months after initial publication.
I won't be sorry to see the Elseviers and Natures of the world fall--but only if the funding that can provide for a competent editorial process can be maintained. With the NIH funding less grants now than any time in the last 15 years, it's hardly the time to be pressing this issue.