Sad thing is, I'll probably still buy it.

I'd be willing to bet that depending on her new book's success, we'll either see more Harry Potter related material or less. If she can venture into new genres with success, it will probably be less likely we see any more Harry Potter themed books from her. I love the world and think there is so much material in that universe that she could so many different routes other than HP and bring new stories hence why I kinda hope this new book of hers falls flat. :P

 I will buy it, its for chariety anyway

 Bummer.  I hate it when a franchise gets milked rather than adding new material to it.  Would you agree Mr. George Lucas???

Well hell! We've always known that. How is that news? I didn't by Beetle the Bard and I won't buy this one. Milking that cash cow seems to work!

I don't have magical powers, but I suspect you will see the return to the Potter universe at some point.  Authors have a hard time putting away their toys.