There's a Nintendo Media Summit going on as I type this, and they've just confirmed that a Virtual Console-like service for 3DS will bring Game Boy and Game Boy Color games to the system, including 3D support (probably something as basic as a 2D layered effect, where the background layer will shrink into the distance, the foreground will appear closer, and the main interactive layer will be sandwiched in the middle)
The 3D camera can take a photo of your face and use it to automatically make a Mii.
3rd party support is a big focus for the system.
3DS will launch in February in Japan, March in the U.S. and Europe. System will cost 25,000 Yen, no word on prices outside of Japan.