Nintendo pushed out their latest 3DS update last week. Version 4.0.0-7U of the 3DS' system software adds the ability to create folders on the Home screen (which comes as a big relief for those of us that have to scroll through all those Ambassador games) and improves navigation in the eShop by adding a second row of navigation buttons to the touch screen.
Of particular interest is "...the ability to update select software, such as the Mario Kart 7 update in mid-May that will resolve shortcut exploits in the game. The update will be required in order to play online multiplayer mode." This is interesting because it means 3DS games (albeit 'select' ones) will be able to be patched in the future and thus Nintendo may be able to avoid a repeat of the Skyward Sword glitch problem that happened back in December.
3DS owners already running system software 2.0.0-2U or higher will be prompted to update automatically while others will need to connect to the Internet and go to System Settings->Other Settings->System Update in order to get it.
SOURCE: Nintendo.com "Nintendo 3DS System Update Info: What's new in the latest system update?"
SOURCE: "New Features Available" Notification sent via 3DS