I follow The Flight Deal and they have confirmed an excellent fare to Hawaii from Newark that was available recently is still available. Living in New York, I know tickets to Hawaii are always expensive and tickets to Hawaii for under $600 are very rarely available.
For certain dates through May 2015, there are tickets from Newark to Honolulu for $573 including all taxes and this is valid for Monday-Thursday departures. You do have to connect in Atlanta, which is slightly inconvenient, but if a trip to Honolulu works with your travel plans, it could be work taking advantage of.
Visit The Flight Deal for more information: Delta – $573: Newark – Honolulu, Hawaii. Roundtrip, including all Taxes
I personally haven’t been to Oahu, but I did visit Maui twice and Kauai once. I really do love the Hawaiian islands and can’t wait to go back. Here’s my trip report of my travels there last December: