Now that three days have passed and folks have gotten a chance to digest Wednesday's rulings, what do they mean to the average person and what still needs to be decided.
The Proposition 8 decision is the clearer of the two in terms of going forward. The Supreme Court found that the proponents of Proposition 8, who were the only people who appealed from Judge Walker's decision did not have the right to represent California in federal court (regardless of their right to represent California in state court). Because there was not a valid appeal, the opinion of the Ninth Circuit (which only applied to California's unique circumstances anyhow) is wiped out and the appeal is dismissed leaving the District Court judgment intact.
Technically, a declaratory judgment case only declares the rights of the plaintiffs, but most government officials will apply a decision invalidating a law as if it applies to all potential plaintiffs. The defendants in the Proposition 8 cases have announced that they believe that same sex couples can now legally get married in California. The only potential problem is that the plaintiffs only named two of the county officials who handle marriage licenses as defendants. Currently, state officials say that all local county officials are required to follow the instructions of the state officials who keep vital records, but you may have a couple of conservative counties where the local official balks. My expectation is that if this happens, any requests that a court order the local official to issue the license will be a state court case and the California state courts will hold that the local county official has to follow Judge Walker's ruling. I doubt the US Supreme Court will get involved in this issue.
The DOMA decision is a little more complex. Technically, the Supreme Court only struck down Section 3 of DOMA which established a rule for interpreting federal statues to eliminate a same-sex spouse from the definition of spouse. The Supreme Court was not asked to rule on Section 2 which holds that one state does not have to recognize another state. Section 2 may be key for some federal benefits, and is also key to state decisions not to give state law benefits to same-sex spouses.
On the federal level, there are two basis types of rules for federal benefits and marriage. Some regulations (including social security) define spouse based on the state of residence (i.e. does your state consider your marriage legitimate), but others define spouse based on the state of marriage (i.e. did you fully comply with the rules to enter into a valid marriage in the place where you got married). The DOMA decision glossed over the fact that, at the time that Ms. Windsor's spouse died, her home state did not recognize same-sex marriage. By glossing over this fact, the Supreme Court left blurry the issue of whether it matters how your state of residence treats the validity of your marriage.
Since Wednesday, the federal Office of Personnel Manage has issued a memorandum outlining the transition for the first set of federal benefits to be extended to the same-sex spouse of a federal employee.
On DOMA, I would expect the next round of cases to attack -- both in state court and in federal court -- the constitutionality of Section 2 (allowing a state to refuse to recognize a same-sex marriage in another state) and any law purporting to deny state and federal benefits to a couple that was validly married in another state but now live in a state which does not allow same-sex marriages.
While there will also be other cases involving the constitutional validity of laws banning same-sex marriages, my hunch is that the Supreme Court will avoid those cases for the time being. If they are likely to take any case it will be about whether states can refuse to recognize a marriage performed elsewhere.