One reason I'm worried is that Shannon and I will almost certainly be reading the book aloud together, which means we'll be reading it very slowly. It'll take us weeks. So everyone else will find out the ending right away, but we'll have to wait. More time to get spoiled.
I can only hope that I don't currently have people on my friends list who consider cut tags and warnings unimportant. I still remember getting spoiled for the end of one of the Buffy seasons by some douche bag who was immediately removed from my friends list. I'm still bitter about it.
That said, I'm excited about the book. We ordered it from one of our local independent bookstores, so we'll no doubt be collecting it on Sunday. Yay!