One of the best sources for this information is the Ca NORML web site. Their list is kept up to date (it already shows Corona & Perris as closed) and lists delivery services as well as dispensaries. Be prepared, with the delivery service you'll be paying extra for their time and gas, and if you drive to Lake Forest, Santa Ana, Anaheim, Palm Springs, Long Beach or L.A., you'll use your time and gas. So, we're pretty screwed either way.
Then again, I realize that the street dealers in Riverside County are probably really thrilled with the RPD and DEA, now that they'll be getting business back from the legal sources that are gone!