I think what I was trying to say in that last post is that it makes no difference whether HP lives or dies, or who else lives or dies in the book; the main thing that is going to be felt on a global HP fan level is a sense of emptiness now that the series is over. It's like coming down from a sugar rush. And some, crazy as it may sound, may need counselling for it, especially if they've been immersed in fan sites, etc.
I've read stories in the last day or so about the Publishing Machine's speculation over what will 'fill the gap'. I don't think anything will, or anything that is consciously marketed to be. I know the HP publicity machine went into overdrive, but the fact of the matter is that the initial frenzy occurred via libraries and schools; it was a slow burner, driven by word of mouth and a damn good story. The Next Big Thing can't be orchestrated, and it shouldn't even be attempted until people have had time to process the fallout from this Big Thing and dealt with the sense of loss.
People who don't dig HP will be rolling their eyes at this. But others will know what I mean. Some people around me are reading HP7 slowly to prolong that exquisite sensation; others, like myself, devoured it in hours. Either way, you get to the end. And if JKR keeps her word (and there's no proof of her ever going back on it), it will be The End. And that leaves a very big gap, right in the middle of your chest.
Pavlov's Cat speculated if millions of people reading the same books at the same time would exert some kind of gravitational pull. I think so... downwards.
More like Harry Potter and the Deathly Hollows.
Watch that space.