Michigan just did the same thing. Too early to tell how its going to turn out.
Massive confusion is the only sure thing. One of the local burbs did a raid on a "clinic". The clinic refused to sell them MJ without the Med MJ card, so they got counterfeit ones and went back, bought some. Arrested everyone, clinic workers, customers, receptionists, the whole lot. Sounds crazy, right?
Surprisingly

rofl

the media left out a "little bit". Apparently they actually were violating some portion of the law, I forget the details, will try to find an article, but stuff like you can only have so many plants, a grower can only have so many customers, etc. So it wasn't a jihad against the MJ law that the media is portraying it as.
Should be interesting to see how it shakes out. I admit I haven't followed the details, cause I don't care if its legal, ain't interested.
The devil is in the details, and the Med MJ proposal on our ballot at least was very short on details, legislature I think had to pass some law with the nuts and bolts of it all covered. The proposal just said you want med MJ allowed or not, essentially.
I'll try to find some documentation, I could be way off as I haven't paid a lot of attention to it. I only got interested after the raid, thinking WTF where the cops thinking based on the articles. Its passed, get used to it, you get paid to enforce the law, not to like it, etc. Dug a little deeper and found there were grounds for arrest after all.
Randy