Welcome to Cruise Mates! Let a Travel Agent know what you want to do. Carnival may accompany the release of new cruises with a press release. You can also sign up for Carnival emails.
I wouldn't count too much on sailing Miracle. Cruise lines often move ships as needs change, new ships come out and other ships go into dry dock. That said, of course, miracle may very well sail to Hawaii in April 2014.
I am sure you are excited. Please ask all the questions you want.
All I ask is a tall ship and a star to steer her by; John Masefield
Carnival: Glory 2004, Destiny 2008, Splendor 2009, Freedom 2011, Valor 2012, Dream 2013
Celebrity: Summit 2011
Princess: Ruby 2010, 2014, Caribbean 2013, Coral 2014, Regal 2014
Star Clippers: Royal Clipper 2015