You should be fine when you sail. Irene will be well north so there should not be much heavy seas, may be just when you leave port for a bit but that is all. Now the only thing would be will the ship be able to go to all ports, that is something that could change, depending on what damage may be after Irene leaves.
Go and have a great time.
Star Princess 2005, Sun Princess 2005
Caribbean Princess 2006, MSC Lirica 2006 , NCL Pearl 2007, Majesty of the Seas 2008, Carnival Destiny 2008, MSC Lirica 2009, Carnival Valor 2009,Carnival Legend 2010, Carnival Liberty 2010,Carnival Fantsay 2011,Carnival Valor Feb 2012, MSC Poesia Dec 2012, MSC Poesia April 2013, Carnival Legend Nov 2013, MSC DIVINA Jan 2014, MSC Divina Oct 2014, Carnival Liberty Jan 2015, MSC Divina Apr 2015, Carnival Ecstasy Oct 2015, NCL Star Jan 2016