The Federal government is not going to be the first to show any progress on the drug issue; the higher you go, the lower quality the discourse, the more reasons there are to say no and the less to say yes - and the current crackdown that's occurring from Obama's Attorney General's office is far worse than anything that happened under Bush. Any reform is going to come from the states, or even the cities.
So, if you're a marijuana dispensary or a dispensary trade association, what can you do to accelerate the reform process? You volunteer to be taxed! You get a referendum on the ballot, and suddenly the city is dependent on you for revenues, and they will defend you to the death. Walter Russell Mead points out that the City of Oakland (where this really happened) now has 3% of its revenues coming from legal (by local law) marijuana dispensaries, and is proposing allowing more to raise this share to 6%. Not a sustainable way to keep the city solvent, but a great model for marijuana merchants in tolerant places around the country. If Eric Holder's goons try to shut down the Oakland dispensaries, the legal apparatus of a major city will turn against them to defend its revenue stream.