Dana Goldstein has a nice piece about how education reform can proceed without mass teacher firings. It seems that Baltimore has agreed to a new teacher contract (with the union) that will experiment with many of the reforms that are being proposed. In particular, I like the idea of defining "lead teacher" as being one per school. This nicely side-steps inter-school competition (where the incentive is to try and shift weak students to new schools) and puts the focus on doing one's best with the students they have. Plus, on an individual school basis it is likely that information will be more complete than would be the case when you focus entirely on standardized test scores.
Mark has noted the odd anti-union stance of even liberal education reform advocates. Curiously, I would hypothesize that if reforms are worthwhile and carefully thought out then it is possible to get teachers to agree to them (even if they are not entirely in the best interests of the teachers). After all, it's not a ridiculous idea that many of teachers went into teaching in hopes of helping children to succeed (those focused entirely on financial rewards may well have chosen other lines of work). But perhaps this is a good example of positive reform. I may not like every element of it but it is at least a reasoned attempt to experiment with modern reforms.