Well, of course responsibility-type laws(ex. seatbelts, helmits, marijuana/alcohol driving, surgery, etc.) will be in effect.
That usually goes without saying.
Even the article itself said... most children say pot is easier to find than ciggeretes and alcohol.
That tells me something that these "Black Markets" are somehow more effective at distribution among children, than regulated legitimate markets that distribute legal drugs.
If we move marijuana off the "Black Market", and onto the "Regluated Market" then I am sure society as a whole will benefit.
Not to mention regluation results in taxation, which again, benefits society. Currently the only taxing on marijuana is done by criminals and unqualified cultivators.
And to top it all off, we spend $7 billion dollars a year on it's enforcement. Didn't we spend less than that on the production of Hydrogen Powered Cars?
Again, if we didn't spend that much money every year, we'd have more money on our hands.