The proposed name for the service is “Smash Bros. Brawl: Challenger” and the content in question is said to include new stages, characters and music. These items will cost Wii points to download, hence it being part of the WiiWare line.
We don’t really have any more information than that at this time and it must be stressed that this is very much ‘rumour’ territory. Still, it would be an interesting way of making more content available to player, although the idea of having to pay through the nose for it after having coughed up the dough for the game itself strikes us as a bit rich.
Also, it would be a confusing move for WiiWare when you consider how keen Nintendo is to ensure the service is a breeding ground for vibrant new interactive experiences.