For which diseases? Because with several states not every disease that can be treated with weed is legal to prescribe someone to.
Well, there's two bills. The less expansive one (which also passed, as an attempt to derail the other one), prescribes specific terminal diseases and seizures, while the "true" medical marijuana bill allowed specific kinds of doctors (the chronic pain guys, for example) to prescribe marijuana for a larger number of diseases.
I'm not sure on what exact diseases, but chronic pain, terminal, and seizure-related diseases are included in the more expansive bill.