if you reserved through Gamestop it shouldn't matter when you reserve.
you haven't seen it? its cool it shows bits of the ruined world with the trainer(you) walking down a waterfall, on the water! then jumping from a normal floor, onto a wall! its cool. it also shows Dialga and Palkia at Spear Piller but then Giratina burts in between the to from the ruined world. it also shows a glimpse of the Frontier and the new Wi-Fi room