Yes, you are right, the problem with Wii sales currently is JAPAN. No matter if they launch a kirby, Mario, Metrois, Donkey Kong or a Zelda game, that the sales will not go up. Dragon Quest X is the only hope left for the Wii (but as you say, not in a close future). The'thing' that could save the Wii may be a posible 'explosion' of the Wii Vitaly Sensor that may skyrocket Wii sales again the same way WiiFit did two yeas ago.
I hope Nintendo finds a solution so they can keep selling Wiis for a long time until we get the succesor.







