This morning, Southwest Airlines announced that they are launching online ticket sales for their new service to Hawai‘i from OAK and SJC. The airline's HNL launch will occur on March 17th from OAK. Service to OGG from OAK will start on April 7th. Service from SJC to HNL starts on May 5th, and to OGG on May 26th. Flights from SMF and SAN, and service to LIH will be announced at a later date.
Further information in this Southwest Airlines press release.