Its a character you create to represent you in certain games. Games like Wii Sports support Miis. They also pop in games like, for example, watching you play a tennis match in the stands.
Yeah well theres only a couple of games that support it right now but I can see this really taking off. IVe already had 3 OTers travel to my Wii lol
EA announced they are using the Sims franchise to make a Mii Sims game exclusively for the Wii, that will probably be when it really takes off seeing as how the Sims is so popular.
Limiting to a certain amount is a good idea for a system that doesn't have ALOT of processing power or space. Think if the PS3 had something like that. EEK!
I dont really like the miis they could have gone alot farther with them. wtf all the faces are happy, no angry faces? and the bodys are too fat and round. I know its nintendo but I still would like to see more hair colors and facial expressions. I did get my mii pretty dead on though.