According to this Kansas City Star article, Missouri just passed a law that guarantees that $6,117 in state and local funds will spent on each student in the state. School districts with low tax rates (I'm guessing mostly rural districts) will be required to raise them to meet minimum state levels. Gov. Matt Blunt (R) says that education spending will be increased by $800 million over the next 7 years. Critics, including the National Education Association, argued that the state had not identified where the increase in funding is going to come from (it's definitely not coming from taxes under Blunt, who hates raising taxes so much that he is trying to gut Medicaid in Missouri) and that the impact of some districts was not considered.
It's obviously hard to know what the impact of this law will be, but the goal to make education spending more equitable is certainly a step in the right direction. And while I'm skeptical of anything Blunt does, shifting the burden of funding from localities to the state is probably a good thing.