Our children have a Game Cube. It is somewhat outdated and the games are getting harder and harder to find. They have a game called "Animal Crossing" and it is a lot of fun for the little ones. There are many good games but getting harder to find. Your son will love the "Animal Crossing" game.
When the Wii first came out I was skeptical as you are now of the unknowns. I did some research and talked to many of the kids selling these things at various stores. What sealed the purchase for us is it will play all of the Game Cube games as well as the Wii games. We bought it for them for Christmas.
They can still play every single game they had for the Game Cube and the Wii is the game player to have by most accounts today. If you want one go to a store like Toys R Us, and ask if they have one, they won't. (they are so popular right now) Ask them when they will be getting some in. They will tell you when the next release is made. be there an hour or so before the release or you will not get one! We got ours at Christmas when NO ONE was finding them. We did not know anyone at the store we just asked the right questions.
As for the games for the Wii, it has almost everything you could ever want and new ones are coming out every day. It will also not be outdated tomorrow when the kids grow older.
Heck, even my wife and I enjoy the Wii sometimes. The games are very interactive and you will not be sitting on the couch, you have to get up and move for it to work right. The boxing game will flat wear your arse smooth out.
