Check out Kevin Carey's report (PDF) and blog post about states using watered-down standards to meet NCLB-mandated "adequate yearly progress" standards without making any actual progress in educating children. This seems like an obvious problem with the law's strategy. A state where political conditions prevent the watering down of standards (or simply the creation of bad standards) is going to be a state that doesn't really need a federal standards-mandate. Conversely, a state where political conditions require a swift federal kick-in-the-ass to do a better job of educating poor or minority children is going to be a state where politicians are eager to drive through the giant loophole of the states being allowed to set their own standards.

To be sure, at the margin a loophole-ridden mandate might have some impact, but at the end of the day if the federal government is going to get into the standards business the logic of the policy is federal standards not just a mandate to create some standard or other.