I feel that the Wii targets 3 untouched groups of the gaming world. One group is our younger society. I had to buy my 6 year old brother an Xbox 360 for Christmas because I couldn't find a Wii for cheaper than $500 dollars. He has two games, Viva Pinata and Star Wars Legos. That's it. Everything else on the 360 is rated M. The Wii has tons of games designed for younger people.
Another group is our casual gaming society. The people that like games that are easier to hop right into. The Wii has many simple mini-games that offer tons of fun.
For all the rest of us more hardcore Nintendo fans we have all of our classics. Something all other consoles do not offer. We have Mario, Donkey Kong, Link, Samus, Kirby, Mario Kart, Super Smash Bros, and all other types of platformers that I'm not mentioning. Sony did have Resident Evil but now it's on every other console and Halo is pretty much done. Thankfully all the platformers are incredible. Know that Nintendo has never been just about getting more money. They have always provided the finest games of the finest quality.