Orlando Informer posted an article today with some good information and some things I haven't seen mentioned here yet. Things like how Kreacher will be in one of the windows on Grimmauld Place and occasionally peak his little head out from behind the curtains. Or how the Cabman’s Shelters will be serving “sausage-focused” food items.
http://www.orlandoinformer.com/2014/rru-special-edition-how-diagon-alley-will-improve-hogsmeade-wizarding-formula/
Kreacher is going to be there?? OMG I must see that! lol