Stephenie Meyer-An Obligation to Uphold?

I would like to pose this question to my readers, and Twilight fans, and fans of any series in general. This is in regards to writers that have stories that have exploded to to pop culture icons; your "designers" of Harry Potter and Sookie Stackhouse, the Forks gang, hell even the Babysitter's Club (and there she goes in the "way back" machine.. They didn't have fangs or witches though, did they?) If they are sincere when they say things like "I couldn't have done it without the fans, My readers are the reason I do this, blah blah blah", does the writer have an obligation to follow up when the demand is there?

I point to Midnight Sun, the unfinished copy of Twilight from Edward Cullen's perspective that was leaked some time ago. On, the writer finally answers the question of finishing this book. And the answer? She's sick of writing about vampires. The more that people push her to write it, the less she wants to. Ok, I understand that it was leaked. And had it not been leaked, we may have never been any the wiser. However, I am one of those fans you thank for your fortune of this empire you've built. And, I feel in some respect, that you have an obligation to finish what you've started. I understand the free will, the frustration of being pushed to do things, and being "sick" of a certain subject. However, take some responsibility for the cult phenomen you have created. Not only is it amazing and you get to be riding the gravy train of all the success, but people want more! That to me should be your greatest inspiration.

I want to hear from you guys now. What do you think? Not only about her, but writer's in general. If they start this freight train a'rollin, do you think they have an obligation to see it through to the end of the line? Or is it completely at their discretion? Weigh in.