ok, so if you've seen the news today, JKR has said that two characters will die that she hadn't planned on, and one will live that she HAD planned on dying...
She also states that she never had any intention of killing of Harry "before the end of book seven" but she also "understood" why an author would want to do that.
very interesting...
feel free to speculate with me.
First of all, I would guess that the character that lives is someone readers have grown close to, such that she decided to let them live... I'd suspect this could have been ron, hermione, ginny, Tonks or Lupin. I suppose it's possible it's Dumbledore as well, but I'm still thinking he's dead.
As for the two characters that weren't going to die, but now do... I would guess it's a related pair... three of which present themselves... the Weasley parents, Tonks and Lupin, or the Weasley Twins...
The news is reporting that "two characters die in book 7" which I think is silly. I expect the count to be much higher. All JKR said was that 2 died she wasn't planning on until now.
As for the "not killign harry until the end of book 7..." she also reiterated the statement that the last chapter has been written for a long time (although she says it's tweaked). To me this makes it obvious that the last chapter is kind of an "epilogue" chapter, detailing the lives of the characters after all is said and done.
Almost certainly Harry would die at the end of this chapter, if it were to completely sumarize the rest of his life. Then, we'd get the whole story, and JKR could avoid the worry of having someone else write a "sequel."
Assuming, of course, he survives his duel with voldemort