Arlene Ackerman is about to become the new CEO of the School District of Philadelphia. She spent six years as Superintendent of the San Francisco schools, a tenure which seems to have been both successfull for improving student achievement and controversial for battles with some school board members.
Big changes often cause controversy, especially when people who've grown comfortable in their roles are forced to start producing.
Philadelphia Inquirer story
Daily News story
Other views on Ackerman
Educational Justice: blog entry by SF school board member
San Francisco Chronicle on Ackerman's resignation
Reason magazine's interview with Ackerman