Not to be a negative or such, but I don't think JK should release anymore Series/Novel/such relating to Harry Potter.
I think the series should end with Deathly Hallows and should not proceed, I'd rather see JK venture on other ideas such as the HP Encyclopedia or maybe some fun Text Book such as Hogwarts: A History.
I think JK should also venture with opportunity to do a different type of novels (or series), that can do just as well.
By the time 10 years come, I don't think HP will be on JK's mind. Also JK has a family as well, and now that she finished and released DH, she should now spend quality time with her family.
STOP THOSE DEATH THREATS!
(Please note, this signature is sarcastic!)