Kratom does make this list, alongside mostly illegal drugs. http://www.deadiversion.usdoj.gov/drugs_concern/index.html This list only matters in that people can cite it when talking about kratom; it has no power of its own. The DEA is doing absolutely nothing about kratom right now, though they could start lobbying if they wanted. The catalyst that is making salvia illegal is a kid that killed himself after smoking salvia. I am confident we will not see a similar catalyst for kratom.
Kratom is legal. The feds can't bust you for selling kratom in the way they can for selling medical marijuana. The FDA currently has jurisdiction over kratom and they would need to argue that it was medication being illegally prescribed, or that it was an unregistered nutritional supplement, or a food that wasn't a certified food.
I think a more likely problem is that medical marijuana dispensaries are doing just fine with their revenue streams and don't want to try anything new.
