Japan, with a population of 120 million people can´t handle sales of more than 100,000 units each week for a single console forever.
The market is just not big enough, that´s why DS numbers are going down. Remember, the Playstation 2 sold about 3.5 million units each year, while the DS sold 4 million, 8 million and 7 million in 2005, 2006 and 2007.
The market can´t handle those sales forever.







