Like all governments, the proper operation of California's state government depends on the good faith of law abiding officials. By law, the governor cannot usurp the constitutional functions and prerogatives of the (independently elected) attorney general, which is what he would be doing if he were able to simply order the AG's office to proceed. The governor cannot fire the AG, either -- so Lockyer has no reason to pay attention to the governor at all if he doesn't want to. In this case, we have an AG who chooses to drag his heels on enforcement, adopting a passive posture and responding only to SF's suit against the duly enacted, voter-approved "definition of marriage" statute which is in the state's Family Code.
What Lockyer and Newsome are up to is despicable but there isn't much Arnold can do about it, except wait while the matter wends its way through the courts. This buys the democrats a lot of time, during which they can do quite a bit of mischief. Until a binding decision is handed down by the judiciary, they can steadily increase the number of homo "marriages" and provide those people with monetary and other benefits at the citizens' expense. By the time the dust has settled on this matter, they will have achieved a fait accompli. Even though these "marriages" may have ultimately been invalidated, the money can't be whistled back too easily and, having come so close to victory, the homos will press their case all the more insistently. This strategy of civil disobedience has been occuring in other states simultaneously, eg. New Mexico. It's been carefully planned and the democrats and homo lobby are now coordinating its implementation.
There is really nothing new about this. In the 25 years following the War Between The States, many American government bodies, both federal and state, routinely went much further than this in their bad faith and corruption. Many Americans simply stopped voting and turnout dropped to the lowest percentage ever. More recently, we've seen a federal AG burn men, women and children to death with no compelling reason to do so, except that she and her boss didn't happen to like them. IOW, there is no system of government that will work if criminals are put in charge. This is the situation we have in California.