Pretty much this.
If you were in the position to buy some pot, would you want to go Sketchy McDealerson downtown, buy what product he has, and maybe be happy with it? Or would you rather go to what can only be described as a Weed Store, a brightly lit storefront that has a wide choice of strains and prices to choose from? Honestly prices aren’t going to change a whole lot, and there’s a good chance dealers aren’t going to be able to compete with that buying experience, forcing them to either go legit, or find a new business to go into.
If I had to guess, the most immediate effect of these passing is that state and local law enforcement won’t bother you for pot. If you were unfortunate enough to run into a federal drug enforcement agent, you might get in some trouble if they decided to bother you about the eighth you are carrying around. The feds aren’t likely to waste too many resources on individuals.