The Hawaiian Airlines fare sale on direct flights from JFK to Honolulu is still live with several dates in December, January, and February pricing at $382 inclusive of taxes and fees. Hawaiian allows you to search by month, making it easy to find dates where the sale pricing is still available. United has not matched the fares on their Newark route, with most dates pricing over $700 per ticket, though I was able to find a few December dates with fares of $434.40 r/t.
In on-the-ground news, Megabus is celebrating their expansion to California and Nevada with a $1 fare sale on all routes during their first week of service (December 12 – 19). You can travel to/from Los Angeles, San Francisco, Oakland, Calif., Riverside, Calif., Las Vegas, Sparks/Reno, Nev., Sacramento, Calif., and San Jose, Calif for $1 each way.