How about NPCs to replace teachers who are not active in the time of their class? How about classes twice in the same day, just in case your user, I dunno, happens to be in a different time-zone where that person can not participate according to their schedule?

How about one that actually works, and being able to teach yourself spells through books, without having to reach a certain level to read a book? How about being able to select your target with a spell? How about a large, but not too confusing map that's accurate with the book or the movies?

How about a sophisticated Harry Potter game that just makes sense?

(Oh yes, I totally flamed all the current HP games on BYOND.)