This would only go into effect if ALL states change the way they assign electoral votes. Even then each state could assign electoral votes however they want. Arnold should not buy into this crap even though it would benefit the Republicans right now, in 2000 we would have lost to Al Gore(shudder)if this was implemented nation wide.
I don't think that is what the California legislation says. It only has to do with how California allocates its electoral votes.
This means that they need states with a total of 270 electoral votes. If they can get the compact passed by NY [31 votes], California [55 votes], Illinois [21 votes], Missouri [11], Colorado [9 votes], AZ [10 votes], Louisiana [9 votes], and MN [10 votes}, it means that the proponents need only 124 votes from the remaining states to make it effective.