nsynchrockerchick is right! The titles have not been released. Don't believe any rumors about titles. I like to speculate as much as the next person, but titles are titles. JKR is the only one who I will believe on the titles of the books.
Besides, what kind of a title is "the fate of the dementors?" JKR doesn't make titles like that. That's like giving away the end of the book. That title suggests that the dementors get it. She'd never write a title that gave speculation to the plot of the book.
Think of the other titles. Philosopher's Stone, Chamber of Secrets, Prisoner of Azkaban, Goblet of Fire, Order of the Phoenix.
When those titles came out, we didn't know what a Philosopher's stone was... or who the Prisoner of Azkaban was. Why would she make a title that tells the plot of the whole book? Her titles are about the mysteries that are SOLVED by the end of the book.
This is FAKE FAKE FAKE! >

Grrrrrrr. Some people just make me mad. Don't believe this garbage.