The Secretary of State puts out statistics on their website of overall registrations, not new registrants. Those statistics for the first eight months of 2014 showed a net negative number of registrants, as it included additions and deletions. So while the new registrant numbers are good for Democrats, bad news for the GOP, I'm not sure they have a huge impact for this election. We should keep in mind that only 35% of new registrants are Democrats, compared to 43% of all people currently registered. So while having 17% of registrants is pathetic for Republicans it's also possible that the GOP has a better shot at the new 47% that's neither Republicans nor Democrats.
If there is good news for Republicans it's that there were only 272k new registrants for the last six weeks before this election. There were 332k in 2010 and a whopping 1,327k in 2012. Those new 2012 registrants voted at a higher rate than people who were registered before and Democratic registrations outnumbered Republican ones by 3 to 1. That likely killed Republicans and cost the party 1-3 seats in congress, the assembly, and the state senate. The new registrants in the last six weeks actually had more Republicans in 2010. I don't think that's the case now, but it'd appear that the GOP won't be hurt much by late registering new voters, as the party wasn't in 2010.
The lack of new registrants fits in with the low primary turnout and lower returns in VBM. The enthusiasm isn't there in California. And lower turnout here benefits Republicans.