In this paper, the authors present qualitative data -- vignettes -- that describe how the professional learning systems and structures have changed for some of California's educators in recent years: organization of teachers within schools as professional learning hubs, management by school principals of the instructional mission, navigation by curriculum and instruction teams within districts, and models of support by providers including county offices of education (COEs). Key questions include: (1) How have school districts designed and implemented professional learning systems to support teachers through the transition to the new standards?; (2) What has been the role of support initiatives for school principals during these years of standards implementation? Are there particular models of support for school leaders that have surfaced that show promise?; and (3) How have the resources that the California Department of Education (CDE) has built around standards implementation found their way into the field? The authors have organized the paper around data reporting from several surveys, three case studies of field-based implementation, and the authors' reflections on a broad set of network structures and technical assistance strategies in California that support standards implementation initiatives. Their conclusions and recommendations are based on converging results from these different data sources.