From the cnet.com:
"At this very moment, I am looking at a paused Legend of Zelda: Twilight Princess game while an Xbox 360 and Playstation 3 are perched alongside the Wii collecting dust. Does that mean the 360 and Playstation 3 are inferior to the Wii or provide a less gratifying experience? No way. But what it does mean is that Sony and Microsoft underestimated Nintendo as well as the consumer base they try so hard to impress. The Wii's success may not have been a surprise to Nintendo fanboys out there, but it becomes more apparent that the Wii's success certainly surprised Sony and Microsoft."