Most of the discussions I've happened to see focus on http://en.wikipedia.org/wiki/Value-added_modeling , because being able to judge teachers is directly useful to school districts and lots of outsiders are interested in the topic. Since the usual approach uses multilevel model (you need to adjust for school-level effects, district-level effects, etc before you can extract a usable teacher-level effect), it's almost Bayesian by default, and if you google 'bayesian value-added modeling' you'll find a ton of material.