Because I am a lemming...

My Harry Potter Spoiler of Doom is: Hermione kills Draco Malfoy in the Forbidden Forest Get your Harry Potter Spoiler of Doom

Hmmm...this one actually *could* happen, as opposed to some I've seen that were really wild - Severus Snape as a barista? Lupin rids the world of Daleks? LOL!

I like this one, though:

My Harry Potter Spoiler of Doom is: Voldemort discovers true love by using Mooncalf dung Get your Harry Potter Spoiler of Doom

Some of the Spoilers of Doom aren't any more ridiculous than any of the other theories floating out there. :c)