Here, at the Hewlett Foundation Blog:

Can the top two primary reverse or at least alleviate polarization? Last fall, at the height of the government shut down, pundits pointed to California’s primary innovation as a model for the nation. Meanwhile, leading political scientists have found little evidence that the extent to which primaries are open or closed has much to do with polarization, and California should be no exception to this rule.

I think the truth probably lies somewhere in between.  Certainly the dynamics are shifting in some districts. Based on Tuesday’s results, at least seven out of California’s 53 House races will have candidates of the same party running against each other in November. For example, in CA-17, in the heart of Silicon Valley, two Democrats will be facing off, with the liberal incumbent Mike Honda defending his seat against a well-funded centrist challenger, Ro Khanna. To take another example, in CA-4, in the rural central Sierra, the incumbent Tea Party Republican Tom McClintock will have to fend off Art Moore, a West Pointer and Iraq War veteran running as more moderate (though still conservative) Republican. In each instance, the challenger will be able to appeal not only to his wing of the party but also to the independents and voters from the other party.

I have also been struck by what I have heard in conversations with several California political hands, people running for office, anticipating running, or managing and funding the candidacies of others.  To a person they see the top two primary as a big deal, one that will drive central tendencies in the state’s politics. They haven’t thought much about the idealism of the reformers or the analytical skepticism of the political scientists; they simply recognize that the rules of the game they are playing have shifted and they are preparing new strategies accordingly.