What incentive is there to change then?
Actually, the incentive to change (because of teacher evals linked to testing, NCLB, etc.) has sucked the creativity right out of teaching. It is more difficult to implement new ideas, because the kids are constantly either testing or preparing for testing.
The best time of the year is after assessments are over. For that month or so, even though summer was approaching and the kids were ready to be out of school, my students would always learn a lot. Hands on history and science projects, career fairs (complete with resume writing, interviewing, skills application), math projects that applied to the real world....we all loved it.