I wish that Stephenie Meyer would finish this. However, I can understand her reluctance to do so. Whoever leaked the story obviously doesn't understand what a true betrayal that was. As an author myself (amateur author that is) I know how personal your writing is and how difficult it is to share it, especially if you don't feel that it is perfect. To have it leaked before you are ready to share it, must have been devastating.
I loved Twilight and it is extremely interesting to me to read it from Edward's perspective. Don't get me wrong, I love Bella, but for me, Edward is the one that has a true transformation in Twilight. The transformation is clearer in Midnight Sun and reading it adds a new dimension to his character.
It moves him beyond the object of Bella's infatuation and really allows the reader to understand the struggle that he goes through.
I have always been a huge fan of vampires, and although Stephenie Meyer takes a "softer" approach to vampires, I have to admit that I am a huge fan of her writing. I am a total Twihard! Here's hoping that one day she will finish this book...