If weed is legalized in Cali:
the price will drop like you have never seen (alcohol during prohibition makes a great example)
growing will become very similar to growing tomatoes (you can find seeds for tons of phenos, but the only people who will grow will be people who are looking for "grandmas garden tomatoes" for taste, potency, etc. - otherwise, just go to the store)
mainstream marijuana will be taken on by major corp cash crop companies - big tobacco, sunkist and other Ag companies (quality will suffer a bit, but Im sure as with alcohol, the more you pay, the better you get)
as time progresses, all forms of cannabis will be bred into autoflowering forms for ease of growing. (its been done with nearly all forms of veggies, I dont see why theyd stop there)