Too bad this wasn’t actually clearly revealed in the final Harry Potter book, but only recently during a public book reading by J. K. Rowling.
“Dumbledore is outed on page xyz” would have been another fine spoiler shirt. ;-)

On July 21, 2007, the 7th – and final – Harry Potter book “Harry Potter and the Deathly Hallows” will be released to the eager public. Speculations are running wild if the author, J.K. Rowling, will send her protagonist Harry Potter to face his death in the last book of the series…

Remember that shirts people were wearing about one hour after the previous Harry Potter was released? Those spoiler shirts read “Dumbledore dies on page 556″…

This time, be the first to spread the news!

Of course I have not the faintest idea on which of the 608 pages Harry has to die – or if he will die at all*. But I’m pretty sure that this will – right until July 20 – not spoil the fun wearing the “Harry Potter dies on page 572” t-shirt before the release.
And, hey, maybe this wild guess is even correct… and how much foresight would that attribute to the wearer of the shirt after July 21?

*Therefore, the text on the shirt and in this posting comes with no warranty whatsoever.