The Wii (probably) could have sold better had Nintendo released in with moderatly more power (PowerPC 970MP running at 1.5GHz and a Radeon X600 for example) and included Wii MotionPlus from day one; because it would improve what attracted people to the console (motion controls) reduce their competitions' advantage (processing power) and still keep the console at a reasonable price (below $300).
Had Nintendo made a high powered system like the PS3 or XBox 360 without motion controlls Nintendo would be a third party publisher today and several (more) large publishers would have gone out of business in 2005 through 2008