Colorado and Washington are already blowing it. They are taking tax revenue from the sale of marijuana and using it as regular tax revenue for programs such as schools. Just look at the insidious relationship government has with the lottery to see that we are just shackling ourselves to a whole other host of compromised interests. Once they get that money regularly, they are never giving it back with out a (corrupt) fight which means any means to use the revenue from drug sales can never be used for appropriate or creative means to further solve the drug problem and we will quickly find ourselves in the absurd situation where our elementary schools will be active drug pushers (see the recent John Oliver piece that highlights a New York Public School ad pushing gambling and the lottery as some noble activity).
It's the one major social issue that can completely fund, to the full extent of current science, the research and treatment of it's ill effects on society...and we are throwing the opportunity away that will be extraordinarily, if not impossible, to get back.