Will the 2012 California Republican primary be "open" to individuals of all parties, or closed to Republicans only?

Last election, the Republicans in California allowed all parties to participate in the their primary. This is always a party decision, and most parties usually keep their primaries closed to party members only. This year, due to Ron Paul’s presence, I am predicting the Republicans would not want those of other parties participating, since it will help Dr. Paul. But I do not know for sure. Will the California 2012 Republican primary be open to all voters or just Republicans this year?