The automatic updates will be issued in an attempt to protect the games console from piracy. However Nintendo makes it very clear that the anti-piracy measures would be secondary to adding new 3DS functionality to the system.
The older Nintendo systems have had a manual firmware update system in place but gamers rarely ask for the game to update itself.
The new SpotPass background update system Will allow Nintendo to download rankings, news updates and even games while the Nintendo 3DS is in sleep mode, with minimal impact on battery life and without any intervention from the owner.
Via Via SlashGear