This is absolutely huge. Imagine how big this would be at USJ if Potter just pushed them to break records...yeah, HUGE!
In the States, there are just so many things to imagine. The attraction ideas are virtually endless (although a lot of them [90%?] would involve involve screens in some fashion, maybe use Musion more), but the merch, the merch opportunities are what have Universal brass really excited, I'm sure. An arcade that looks and feels like it belongs in a theme park, Mario/Zelda/Pokemon are merchandise dreams, Mario snacks (candy mushrooms, giant chocolate coins), the list goes on. Nintendo could very well rival/surpass Potter in merch numbers.