Ah yes, this game. I tried to trade in for this game on sunday at JB hifi and the guy said that it was delayed. Went to the other stores like GAME, Ebgames and none of the stores had it either. Apparently, it was known as early as 18th june but no one told me about that.
btw, it is not an xbox 360 exclusive anymore (well in japan anyway), since they are releasing an enhanced ps3 port of the game causing japanese xbox 360 owners to rage. haha.