Got this email from Royal Caribbean- they are allowing CAS members to book before the sailings are released to the general public in 2 days (March 19, 2015):
As a valued Gold Crown & Anchor Society member, you get an exclusive 48-hour window to reserve Royal Caribbean's newest Oasis Class wonder, Harmony of the Seas, before anyone else. You'll be among the first to sail Harmony's inaugural season from Barcelona, and the first to experience her new onboard adventures.
Some highlights of the ship vs Oasis/Allure:
Three thrilling water slides offer an exhilarating series of twists and turns three decks high.
New restaurants, technology and more across seven neighborhoods.
Harmony of the Seas sets sail May 2016 from Barcelona on 7-night Western Mediterranean cruises. Or, board in Rome (Civitavecchia) and sail round trip from there. She will make her USA debut after a October 2016 13 Day transatlantic cruise from Barcelona to Ft. Lauderdale.