Nintendo Wi-Fi connection is finally available for the Wii in Europe as well.
The only game so far that supports multi player games via Wi-Fi in Europe is Mario Strikers Charged Football. Not my kind of game, but more Wii Wi-Fi multi player games are on the way.
I am a bit disappointed that there are no Wi-Fi games available in the online store but I hope that will change. After all, a multi player game does not need to be large to be fun to play together.