It'll be interesting to see what, if any, effect this has north of the border in British Columbia. Marijuana decriminalization and legalization has often been discussed in Canada, but one of the main arguments against a change in the law is that the United States would not approve. Seems like that may be changing.
Felons can't go into Canada (and, there's customs search too), so BC as drug tourist/reup spot doesn't make as much sense as Vancouver WA drug tourist/reup spot.
(although I can't imagine anyone buying retail ounces and then selling them, legal supply chains tend to cover up illicit ones running in parallel, or allow diversion, so I could see the underground taking advantage of this.)
When I was 19 year old non-felon, I took a trip from my home in Seattle to Vancouver BC just to take advantage of the difference in the legal drinking age.
If booze tourism exists, even to a small degree, we'll have pot tourism, even to a small degree.