I've discussed this before, but this Register editorial makes the case a little more comprehensively. Attorney General Eric Holder (who may or may not be personally enthusiastic) has announced that the DEA will stop doing raids on medical marijuana patients in states that have medical marijuana laws. This is only sensible in that the government has limited resources and going after sick people and those who provide them their medicine is a huge misprioritization (is that a word?) of resources.
The next step we should hope for (indeed, demand) is "rescheduling" of marijuana so doctors nationwide can prescribe it legally. Marijuana does not meet any of the criteria required to put a drug or substance on Schedule I, the most restrictive schedule under the (unconstitutional) Controlled Substances Act, so keeping it there is actually a violation of that law. (In fact a strong scientific case can be made that it shouldn't be part of the CSA at all, but I'll take whatever tiny piece of reform we can get.) Keeping an efficacious medicine from sick people who could benefit from using it is incredibly cruel. The whole War on (some) Drugs is cruel, of course, but punishing sick people is downright vicious.