Only One Friend Code for 3DS
Part of what makes online gaming on Nintendo consoles such a hassle is that tedious Friend Code system. If you want to play with people you know, you have to enter lengthy multi-digit codes just to add them as a friend. And while some games do support randomized play for online games, there are usually restrictions in terms of the game modes and available characters.
Nintendo 3DS is doing away with the game-specific system by featuring a single Friend Code per 3DS. Register a friend, and that person will automatically be added to any games sporting online multiplayer that you own so long as they own the same game(s).
Though it's still a bit strange that Nintendo continues to use the Friend Code system as opposed to usernames, the new friend registry beats having to enter those 12-digit codes.