When one looks back at the gaming community before 2006, one sees a very different picture from what is going on today. The Xbox 360 and PS3 had just made their debut, and the race for graphical horsepower was still a major factor when assembling a group of software developers.
Before the Wii, motion control gaming was limited to rumors or simple technology demos. The game pad was the most popular way to control on-screen characters (besides a keyboard and mouse). So, the control scheme utilized by the Wii was a long time coming. The control stick dubbed the 'Wii remote' turned out to be essential for cheap-but-fun motion-based gaming. One could hold it sideways like a steering wheel or straight as is most common.
As the life of the Wii went further forward, Nintendo released the Wii motion plus accessory, which was an optional add-on to the Wii remote controller. That addition allowed games like Wii sports resort and The Legend of Zelda: Skyward Sword to utilize 360 degree detection of the x,y, and z axes that the Wii remote was tilted in. This gave motion-based games a huge boost toward betterment.
Before motion plus was added to the Controllers, the Wii's motion detection methods were very limited to what could be done with the sensor bar and the z-axis tilting of the Wii Remote. After motion plus, one sees less glitches in most games, and Nintendo even proved that the sensor bar isn't really necessary in The Legend of Zelda: Skyward Sword.
One of the big selling points of the Nintendo Wii was that it could bring families together in front of a TV set to engage in motion-based games and activities. Sony had tried a similar marketing scheme before with it's Playstation 2, but it paled in comparison to the success Nintendo had in this field.
The Wii affected almost every aspect of the gaming community when it first gained popularity. Microsoft and Sony jumped on the motion gaming band wagon after it's success was tested, but neither Microsoft's Kinect, nor Sony's Playstation move has matched the notoriety that the Wii has gained.