From its very beginning, the i3 fund, a $650 million pot of cash set aside for competitive grants as part of the ARRA, was intended to be a public-private partnership between the Federal DOE and private philanthropy. The wording of the bill specifically states the i3 grants will only be given out to those able to secure matching funds.
Today it was announced that 12 major philanthropic donors - including the Gates Foundation and Walton Family Foundation - will put up $506 million in matching grants. It was hardly a surprise to see this formally announced; the Office of Innovation and Improvement, created under George W. Bush, was designed to operate like the various venture philanthropies.
From the AP: