This paper presents the Center for the Future of Teaching and Learning at WestEd's 13th annual report on the status of the teaching profession in California, focusing on the role of the principal in supporting teaching quality. More specifically, the report discusses fiscal and policy trends, the competing demands of the principalship, implications of budget cuts for principals and teachers, and the state's teacher evaluation system. The report draws on numerous data sources, including a statewide survey of public school principals; interviews with principals, teachers, district officials, and state-level education leaders; and analyses of secondary data, including the limited data available on the composition of the state's teacher workforce. The Center for the Future of Teaching and Learning at WestEd believes that in this challenging high-stakes environment, ensuring teacher effectiveness is fundamental to helping students reach today's high academic standards. The report offers recommendations to address the following four areas identified as essential to support teachers, principals, and policymakers in improving education outcomes for all students, particularly as the state and local districts prepare for delivery of the Common Core Standards: (1) Reinvent evaluation and support for teachers to focus on student learning, with the goal of improving both teaching and learning; (2) Reinvent evaluation and support for principals to focus on improved teaching and learning, as well as improvement of their own practice; (3) Support both principals and teachers in transitioning to the newly adopted Common Core Standards; and (4) Ensure that California has a trustworthy and easily accessible data system for teacher and principal information. Appended are: (1) Research Methods; (2) Additional Graphs and Source & Technical Information for Secondary Data; and (3) Source & Technical Information for Survey Data. A glossary is included. (Contains 65 exhibits and 45 footnotes.) [For "The Status of the Teaching Profession 2011. Summary Report," see ED527744.]