Nintendo released a lot of information on the 3DS at a press conference in Tokyo last night, like the February 26, 2011 Japanese release date (USA release date is still unknown but will probably be March of next year) and will cost ¥25,000 or $300 USD.
The system will come with a charging stand, a stylus, a 2GB SD card for storage, and cards that, when viewed through the front-facing camera, become augmented reality images.