In a revelation that could only be compared to a certain young man finding out an evil Sith lord is his father, producer Justin Dowsedell for Next Level Games has confirmed that Friend Codes will not be game-specific. Rather, your code will be connected to your Mii, allowing you to keep the same code from game to game as you play in Nintendo's online catalog of games.
"Each Mii created generates a Mii code that never changes. This code will thus be used for all other online games in the future," comments Dowsedell. And with each Wii console holding up to 100 Miis, there are one trillion possible 12-digit friend codes, leaving plenty of possible Friend Code combinations up for grabs.