The Bill & Melinda Gates Foundation recently announced a new open access policy that will apply to all articles based on research funded in part or entirely by the Foundation. The policy will require all articles to be freely available online with a CC-BY (or equivalent) license. A 12-month embargo period will be allowed until January 2017, at which point all articles will need to be available online at the time of publication. The policy also applies to data underlying the research results.
For more information: http://www.gatesfoundation.org/how-we-work/general-information/open-access-policy