Nintendo announced during their TGS presser that they will be adding a firmware update to the 3DS very soon, and that it will give players the ability to record 3D videos with your 3DS camera(s).
The update also includes an update to the 3DS eShop, and an update for the Mii Plaza (via Andriasang).
Nintendo announced that “new experiences for people who have conquered all the StreetPass challenges in StreetPass Mii Plaza” were on their way to the 3DS as well.
Nintendo gave a lot more shocking info earlier today: Monster Hunter 4 was announced as a 3DS exclusive, details on the add-on slide pad were given, and a lot more, like release dates, screens, details and videos for upcoming 3DS games. See all those updates here.