I do not think it will end prohibition for recreational use but it will cause an avalanche of other states growing it as well. As an example, S. Dakota has had hemp legalized for a long time. The only reason they didn't start is because the feds, in particular the DEA, said they would prosecute the farmers under federal law. With property seizure laws that is no idle threat.

One effect that bringing back hemp will do is re-educate people about the real history of this plant and it's uses. Then maybe people will realize just how badly we got screwed when they prohibited it in the first place. Goin' to be some irate people when that happens.

Another is growing it for fuel. Legalizing it means that hemp will be grown for fuel, giving California's farmers a shot at a $60 billion a year market. Ethanol from hemp will compete very favorably against oil. There are advantages to car companies in not having to retool their entire plants, billions in savings to them. According to Popular Mechanics (May 2006) The Truth About Biofuels, they state that in order to replace oil with ethanol from corn we "would need to dedicate 675 million acres, or 71% or our nations farmland, to growing feedstock." Corn produces roughly 300 gallons per acre and needs pesticides and herbicides. Hemp produces over 1000 gallons (using 1890's technology) and needs no chemicals. This means that 71%/3.1= 22.9% of our farmland for hemp to achieve the same goal. That would mean stopping the farming "soil bank" and having that land dedicated instead to hemp.

We could all drive SUV's to our hearts content. If fuel prices rise we would just grow more. Many people believe this is why "marijuana" is illegal today.