If you watched The Hidden Secrets of Harry Potter on A&E last Sunday, then you know that I'm pretty much just echoing what they said.
Anyhow, one of the things that was brought up was how wrong Harry, Ron, and Hermione were about some people throughout the series. For instance-in the first book, the trio think Professor Snape is attempting to steal the Sorcerer's Stone and even hex Harry's broom at a Quidditch game. But we all know that it's Quirell who was after the Stone for Voldemort. In the second book we're wrong again about the Defense Against the Dark Arts teacher--in fact we find out he is a complete fraud. But that was suspected--really what we were surprised is how nasty he turned out to be--modifying those poor people's memories and then stealing their stories. In The Prisoner of Azkaban we find out the DADA teacher is a werewolf. And that Sirius Black is innocent. In the fourth--Moody, the seeming ally and auror--turns out to be someone completely else! And we are fooled again by Umbridge in the fifth--at first she seems just somewhat foolish, funny, and boring. But shortly afterwards--we see what she really is. A very, very nasty person and a control freak with no limits. And in the sixth-we arrive at Snape.
Since Harry has been wrong about all past DADA teachers, is it possible that he is wrong about Snape? Is it possible that Snape killed Dumbledore on his own orders? Or made it seem like he was killed? (Check out more theories at http://beyondhogwarts.com)We know that the director of Prisoner of Azkaban had it okayed to put some spoilers for the seventh book in the movie. Could it be that in the scene where Lupin transforms into a werewolf, when Snape comes out of the Womping Willow, and he sees Harry, Ron, Hermione--his instinct is to immediately protect them, it is actually foreshadowing that in #7, Snape will actually work to protect Harry? Even though Snape says in The Half Blood Prince to Bellatrix, "Do you disagree that murdering his favorite student might have turned him against me?"
Well, this is only one theory. And it's the one that puts Snape in the best light. Personally, before really considering it, I was disposed to think that Snape was a definite bad guy. But then I read #6 again--and it made me reconsider. However, we still don't know that much about Snape.
We have no idea right now as to who he's working for--he could be spying on both Death Eaters and the Order for a third party we don't know about! Anyway, this is just an idea.
Guess I'll have to wait ten more days to find out the truth......
ps. Some of my other theories are: Hermione and Ron will get together, Fleur's and Bill's wedding is going to be hilarious, and we haven't seen the last of Dumbledore yet! And well, it's not a theory--but I hope the Weasly twins will find a pair of lovely wizarding ladies who are just as devilish as they are.