The official website for Universal Orlando Resort's upcoming
Halloween Horror Nights this fall stated that The Wizarding World of Harry Potter — Diagon Alley attraction will not be open during this event, set to take place between September 19 - November 1, 2014.
So for those interested in attending HHN this year, do take note that the new Diagon Alley attraction at Universal Studios Florida will be closed at that time. There is still no set opening date for the The Wizarding World of Harry Potter — Diagon Alley, but there will be a VIP and media event next week, attended by cast of the series (including Helena Bonham Carter, already
confirmed), as well as SnitchSeeker, who will be covering all the festivities live from next Tuesday on.
Additionally, the large walls blocking and barricading the London facade hiding Diagon Alley were taken down on Monday, though there are still small fences stopping guests from actually entering the Wizarding village and King's Cross. Some of those photos of the London facade in plain view, from Inside the Magic, can be seen here.