Okay, a few things:
1.) The quote was "Neither can live while the other survives" not "Neither can live without the other" They are two different things.
2.) After watching/reading many interviews given by JK, I would like to say, she has stated that she will not continue with Harry's story, BUT she has tons of information in her notebooks she has not yet put in (such as Dean's history that never found it's way into the stories) so she has said she might put all the leftover stuff together to make an 8th book...but the 7th book is indeed the end of Harry's "Adventure".
3.) I don't believe Harry will die. First of all...I fully believe in the clues and statements both Ben Schoen and Emerson Spartz have put together. If you would like to watch their information and be taken over "to their side" xP Just look up Emerson Spartz on Youtube, and you'll find some of the debates they have up. (In case you don't know, Emerson and Ben are the founders of Mugglenet.) I would rather you just watch those, than me repeating it all. They say it so much better <3
The Order of the Phoenix: A Harry Potter Guild