If a classroom is only an assessment-related classroom, the focus becomes only the measurement of skill. That's the only thing that is measurable, because it can be identified clearly within students abilities. For instance, as a reading teacher, I can figure out how well my students do in the following skills: main idea, compare and contrast, drawing conclusions, etc, etc. These are identifiable and measurable through a test. And, in fact, it's good to measure them: we're able to see how well a student can comprehend and, indeed, chew, savor and swallow a text that way. All these things are gateway drugs: we gather ourselves into reading through comprehending, which makes us enjoy things like beauty and language. But when we only measure those skills, then we falter where things really count: the synthesis of skills, namely writing, and projects, which usually takes the content we learn and wonder about and synthesizes it with a skill such as drawing conclusions based on information gathered, making inferences about character motivations, etc.
I also wonder how intensely the replacement of DCPS standards with Common Core Standards are going to affect how we measure skills, and how we teach. I like the holistic (err...whole-istic?) approach, but is DCPS doomed to be a testing culture because of value added? In the next five years, it looks like. Ugh.