According to C&EN, the NIH has issued a rule that publications resulting from NIH funded research be submitted to PubMed Central for posting.  Naturally, organizations with copyright interest in published research is  less than enthused by this ruling.

What has happened over the last century is that a sizeable publishing industry has grown up around the publication of periodicals specializing in scientific research.  In exchange for release of copyrights, authors get free or nominally priced access to publishing and distribution of their work. For their part, publishers tap into a continuous stream of refreshed content that is virtually free of charge. 

Counterbalancing the low cost of content are the sad facts of subscriptions.  Many (most) journals suffer from low distribution numbers, so the zero cost of content helps to keep overhead down, but publishing and distribution costs cannot benefit from the economy of scale.

The special interests seem to be sitting in watchful waiting, but they have raised the issue of copyright. Their concern is that they are being forced to distribute their property by the strong arm of NIH without the chance for reimbursement.  This could resolve to a property rights battle and as such, I can’t imagine that the NIH would prevail in the courts.