On Friday 21 November the Bill & Melinda Gates Foundation adopted an open access policy covering all research funded by the foundation. The policy takes effect on 1 January 2015. The foundation is one of the very largest American funders. The policy covers not only the results of funded research but also the research data themselves. For more, see:
http://www.gatesfoundation.org/how-we-work/general-information/open-access-policy