So it looks like some Wii online multiplayer will be pay to play. This will be indicated on the boxart. A blue WiFi Connection logo means free to play, a red logo means pay up, sucker!

http://kotaku.com/359754/nintendo-announces-wii-pay--play

Now I am just wondering which way Nintendo is going with this. I mean, I dont really see the point in offering a pay to play subscription service because I kinda doubt it will be worth it' s money (In comparison to Xbox Live). Also, Sony is offering already a decent online service that is free, so I guess that, in the end, you will have to pay for something if you own a Wii, that you get in similiar quality on PS3 for free and in much better quality for a bit more money on Xbox 360. Anyway, that' s just speculation, I want them to announce a feature list!