It's largely about the Prophecy that Trelawney made, but it touches heavily on Dumbledore, especially, as well as some other things.
I don't agree with everything here, but I think all of it is very interesting, and well thought out... and in any case, worth reading, if you're a Harry Potter fan and like this sort of thing. :)
I'll get around to reading the other essays on this site, I'm sure, but for now..
Click!