First, Vicki Phillips and Carina Wong explain the overall strategy in an article on "Tying Together the Common Core of Standards, Instruction, and Assessments" in the February 2010 Kappan (scroll down to the "Features"). Respectively, they are the Foundation's director of education and its deputy director for College-Ready Work.
Second, the Foundation press release from last Thursday, begins:
The Bill & Melinda Gates Foundation today announced 15 grants totaling more than $19.5 million to support the development and testing of prototype classroom assessments and instructional tools in math and literacy to help educators better prepare all students for success beyond high school. The investments are part of the foundation’s support of the effort to build a coherent system of consistent college- and career-ready standards, aligned assessments, and teaching tools to strengthen teacher effectiveness and dramatically improve student achievement.The Prichard Committee project blogged here is a piece of this larger effort.