Are Prince William and Kate going to a Creole-speaking island for their honeymoon? What kind of Creole do they speak there?

Yes, I heard the news.  The Duke and Duchesse of Cambridge are in Seychelles for their honeymoon.  I hope they brush up on their Creole.
Just like Haiti, the Creole of Seychelles is based on the French language.  The Seychelles Creole is very similar to Haiti's.