skullaria wrote:
Some of the more tantalising tid-bits she let fall are that although Albus Dumbledore – the headmaster of Hogwarts School of Witchcraft and Wizardry – was murdered in Half-Blood Prince, he would still have an important role in the final book, and furthermore, his killer Severus Snape (whose role is assayed by Alan Rickman in the Harry Potter films) is actually a good character.

Daniel Radcliffe stars as Harry Potter in the film adaptations of J K Rowling's phenomenally successful Harry Potter series
The latter bit, which had been a topic of much debate and speculation among Potter fans, was first voiced at the concert by author Salman Rushdie, who offered his theory that Snape and Dumbledore were in cahoots (over the latter’s murder) and that Dumbledore’s death was a hoax.

“In my opinion, Snape is good”, he declared.

Rowling’s answer: “And your opinion is right, but I feel I need to make one thing clear about Dumbledore: he is dead.”

Other items the usually-reticent author let fall were that Harry’s hateful aunt Petunia Dursley would have a very important part in the final book, and heavily implied that Harry and his two friends Ron and Hermione would survive in the book, whose title Rowling is still thinking up.

Rowling also said – in response to Stephen King’s question whether Harry Potter’s rival Draco Malfoy would be redeemed – that all her characters, barring the villain Lord Voldemort, “appear redeemable” and that Harry firmly believed that Draco Malfoy was not evil. This may or may not point to her claim earlier this year that while writing the book, one of her characters had been redeemed whom she hadn’t thought of redeeming earlier.

Later on, at a meeting with fans, Rowling also said that the final book would explain the deep connection between a wizard and his wand."

ha I was right I knew Snape was a good character
thank you Mr Rushdie
Snape loved Lily so hates Voldemort for killing her plus any knowledge of Joseph Campbell suggests that Dumbledore wouldn't be wrong especially in such an important matter as trusting Snape
these books fall clearly into the good v evil, in a broadly Christian paradigm, bracket and so in that convention it would be very unususal to have the teacher/father/wiseman/Gandalf/Obe-Wan character be wrong about the importance of love and trust in the good of people