This Gadfly story about human capital in Boston is worth lingering attention. Apart from the drama related to the report's release, it shows how policies and contracts can clearly--and tragically--inhibit a city's ability to improve the quality of its teaching corps.
You might also want to check out this very good analysis of the situation by Michael Jonas of CommonWealth. He goes into more detail about the findings and their implications and has important thoughts about the politics of this all.
--Andy Smarick