I was recently re-reading the Lord of the Rings Trilogy when I noticed something that suggests that JKR probably didn't make horcruxes up. In LOTR, it is widely known that Sauron couldn't be completely killed because his life was bound to the ring. So the only way to get rid of Sauron to make sure he never came back was to destroy the ring. Soo...destroy the ring and Sauron dies, destroy the horcruxes and Voldemort dies. Hmm...
And if we're going along in the same vien, (not that I'm a Dumbledore's not dead supporter for the most part), Gandalf supposedly "dies" at the bridge of Khaza-Dum, but he is later revived by the Valar who say he has work that needs to be finished. While I believe that Dumbledore is dead (the portrait appearing), this is another coincidence that could lead to something.
Lastly, I can't remember where I read it, but Gandalf says to Pippin at some point that death is not something to be feared, just another path, which is one we all must choose at some point. Sound like Dumbledore saying death is just the next great adventure?
Just some things to think about.