Nintendo president Satoru Iwata has revealed that it is possible for the Wii to exceed the total sales of the PS2 as there is a lot of room for expansion. He added that the software to be shown at E3 2009 will show how they will achieve this.

“What we are looking at are the cumulative Wii and DS sales through the end of 2008. Wii has been selling at industry’s record pace so far, and with new customers acquired by the gaming population expansion efforts, it is not impossible for Wii’s total sales to exceed the final install base of PS2. Wii still has much more room for expansion. We can expect more sales of software in the next fiscal year than in the current year. With what kind of software is Nintendo going to achieve this goal? Well, it will be shown at E3 to be held in the U.S. this June.”
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I really wonder what kind of "software" they're taking about. I'm guessing some type of media channel (TV, online radio, mp3, avi, etc) to turn the machine into more of an all-in-one entertainment center.