I thought this was interesting in light of the Malcolm Gladwell article on teachers. I'd read similar things to what you posted Grinity: 1) there's a link between good teachers, strong verbal skills and deep subject knowledge 2) 50% leave within 5 years. It'll be interesting to see how this works out for D.C. and implications for other school districts. Our district web site had an article today about teachers who achieved national board certification.
http://www.washingtonpost.com/wp-dy...4/AR2009010401534.html?wpisrc=newsletter

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At the heart of Chancellor Michelle A. Rhee's vision for transforming D.C. schools is a dramatic overhaul of its 4,000-member teacher corps that would remove a "significant share" of instructors and launch an ambitious plan to foster professional growth for those who remain.
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Rhee's plan calls for introduction of the program, but not before trying to turn over a significant portion of the instructor corps. She had hoped to winnow out poorly performing teachers by weakening tenure protections in exchange for higher salaries. That proposal remains the subject of stalled contract talks.