1up reported today that Nintendo had a surprise press conference. At this press conference they revealed a brand new online service. This service functions a lot like Playstation Home, in that it let's you create an avatar and bring that avatar online into a virtual community.
Since every Wii comes with a copy of Wii Sports, it allows an option for everyone to play Wii Sports together with their Mii's. The players don't have to load a level or create a party to play Wii Sports together, the community offers stadiums for baseball and boxing rings for boxing. You can seamlessly walk into a match of 2 people as they box, etc.