Having school-level instructional teams is one tool that has helped San Diego's Chula Vista Elementary School District succeed with English-language learners, according to a long-time administrator in the district.
John M. Nelson III, the assistant superintendent for instructional services and support in the school district, writes in the May issue of The School Administrator, that school-level instructional teams have helped each school to tailor teaching and learning for that site.
In Jan. 2010, I wrote for EdWeek about how implementation of response to intervention, a multi-tiered approach to supporting struggling students, had helped the Chula Vista school district succeed with English-language learners. A third of that district's students are ELLs. I didn't mention in my article how school-level instructional teams supported that implementation.
For any school district wanting to replicate the success of Chula Vista with improving the academic performance of its students, I recommend that you read Nelson's explanation for how instructional teams work there. The teams include the school principal and a subgroup of teachers—usually representatives of each grade level. They've produced some frameworks to support learning, such as content and language objectives derived from the state's standards for each discipline and grade level.
This sounds like the kind of work that ELL experts are suggesting will need to happen as states implement the common-core standards to include ELLs.