The book will start witph Harry making his way back to Hogwart’s for his final year and his scar will be hurting. Ginny and Ron will be flirting a bit, while Harry tries to take himself seriously by almost swearing. There will be loads more unedited, not very interesting back story that should have been cut and there will be a ‘terrifically, exciting denouement that I can’t reveal as I don’t want to spoil the plot in which two much-loved characters die’. Oh, and JK will make another fortune.
And then Christians, forgetting about the lions once more, will again ask for the pyres.
No, wait! I have the ending! Voldemort reveals that he is, in fact, Harry’s father, and that he expects Harry to join him. Harry, of course, refuses, and in the ensuing fight he loses his arm.
Later Ron marries Princess Leia. Or somebody.