I found a blog called Quoth the Maven several months ago when I was surfing for Harry Potter theories. The blog is written by Janet Batchler, a faculty member at Act One, a scriptwriting workshop, and a Harry Potter fan. She's written a series of set-up/pay-off posts about the books so far.

Back in September she wrote:

As a screenwriter, I know the importance of set-ups and payoffs, of setting up everything that I as the writer want to have any kind of emotional punch later, of paying off anything that I may have set up, and of avoiding inadvertent set-ups that lead an audience to expect something that I'm never going to give them. I teach the importance of getting your set-ups and payoffs straight in Act One, using movies like Groundhog Day, Aliens, and Back to the Future. But this year I found myself referencing Harry Potter, for those enlightened students who had actually read the books…

Now, of course, we can't know all the payoffs without Book 7 in hand. But that's part of what makes it fun — after Book 7 is out, the exercise will just become a final exam question for Children's Lit 101. Now we get to speculate, see what the payoffs could be, try to guess which are the real set-ups deserving of payoff, and which are the red herrings.

Here are the most recent posts:

• More Magical locations
• How Safe Is Hogwarts?
• The Cup. The Snake. And…?
• More on Snape: Legilimency and Loyalties
• Severus and Harry

If you have the time, I encourage you to go all the way back to July 2005 in her archives.