The NIH Public Access Policy ensures that the public has access to the published results of NIH funded research. It requires scientists to submit journal articles that arise from NIH funds to the digital archive PubMed Central (http://www.pubmedcentral.nih.gov/). The Policy requires that these articles be accessible to the public on PubMed Central to help advance science and improve human health.
[From Public Access Homepage]
overall, this will be an interesting thing to watch and track, as it will hit certain publishers, likely the smaller and middling medical publishers, more than others and thus drive market consolidation and prices for journals up. at least that is my expectation.