Washington state just recently joined Colorado as the only two states that allow retail sales of marijuana for personal consumption. Washington DC just recently decriminalized marijuana for personal use. Also there are 23 states and the District of Columbia that allow marijuana for medicinal purposes.
What do I think the prospect of marijuana becoming legal in Tennessee? I would say, "Don't hold your breath!" Tennessee is just to conservative a state to think that will happen anytime soon. Medical Marijuana, maybe, but not full legalization. It will take the power of the people to rise up and say they want this change, which probably will not happen.
The Tennessee legislature took up the issue of medical marijuana, called the Koozer-Kuhn Medical Cannabis Act. It died in a House committee and was the Senate took no action on it when the legislature adjourned.. Tennessee did take a small step towards legalization when it came to possession of low THC oils. Its a long story, but the gist of it is as long as you are a part of a study to see if it works, you can possess the low oil for medical purposes. The question then is, when will the studies actually begin.