We have a lot of friends who have been staying onsite at Universal in recent years and they really like the hotels there a lot. All good things to say. We're staying at Hard Rock as the boys are most interested in it.
And no... you are not crazy! The shops sound great. Honestly I remember thinking when we went to Hogsmeade that they really missed the boat with merchandise - there was some, but could have been more, and what shops they had were so small it was hard to get around inside them (of course we were there peak season which didn't help). It sounds like they are going to remedy that in Diagon and Knockturn Alleys and even go back and enlarge the candy store in Hogsmeade, which is good.
We liked the Three Broomsticks (had lunch there), looking forward to both the Leaky Cauldron and Fortesque's too!
The only thing that seemed a tiny worrisome is that they seem to only have 2 rides, the Hogwarts Express and the Gringott's Bank ride. It sounds like they are adding an Ollivander's on the London side that can hopefully hold more people. They really could use 1 or 2 more rides on the London side. I hope they plan to add them.
ETA: The new website is very cute too, although it keeps crashing on me when I try to click the alleys. Probably too many people!