Probably the most horrible and yet somehow the funniest prediction regarding Harry Potter that I have seen as of yet:

This is how the 7th book and movie will ( or should ) end: There is a huge fire at the Dursley's House ( the "muggles" that hate magic ), and, when the firemen hear a noise from under the stairs, they break through and find Harry, at 21 years old, talking to himself, and because he says stuff about magic and wizards, etc. he gets sent to a mental institute, IE, the whole story, all 7 books/movies turn out to be Harry's imagination while going batty locked under the stairs, his scar being from brain damage.

Dave Morganton, North Carolina (Sent Friday, June 01, 2007 1:24 AM)

From Harry Potter Predictions.

I can't get over how many people think a) Dumbledore is not dead, and b) Harry is a Horcrux. Personally, I think both ideas are rubbish but I suppose we will have to wait and see. Also, just for the record, I still think R.A.B. is Regulus Black.