The only thing I care to add to Sam's excellent - and sadly, all too accurate critique of the problems with our educational system - is that standards for prospective teachers should be markedly raised. When GPA requirements for those intended to teach 90% of the citizenry are invariably the lowest on campus of any professional school, that puts into place a negative feedback loop that guarantees the perpetuation of systemic mediocrity.

[BTW, that situ is not unintentional - plentiful, cheap and mediocre is an educational personnel policy of the states going back to at least the 1940's when they were expanding teacher's ed programs at state universities and land grant colleges from which many state universities grew. Probably good enough in 1938 when most of the population did not need to graduate High School to be gainfully employed, productive, citizens. Not so good in 2008]